Emulating Ed Whitlock’s training: a follow-up

November 29, 2015

Over the past two years I have written on several occasions about the training of Ed Whitlock, without doubt the greatest elderly distance runner the world has ever seen; the first and only 70 year old to run a marathon in less than 3 hours and holder of the age-group world marathon  records for ages M70-74, M75-79 and M80-84, together with the M80-84 world records for  1500m, 3000m, 5Km, 10Km, 15Km and half-marathon,  and numerous other records.  While may factors, including genes for longevity and intense training in early middle age probably contribute to this phenomenal ability, the striking feature that sets him apart from all others is his approach to training: he runs for up to 3 hours per day at a slow pace, many days a week, and in addition, races fairly regularly over distances ranging for 3000m to 10,000m. His overall training program can be regarded as the ultimate in polarised training.

Whitlock himself makes no special claims for his training, other than noting that it works for him.  Apart from having an uncle who lived to age 107, there little that is remarkable about his background or his physiology that might explain his phenomenal distance running ability.  When assessed at age 70 he had a VO2 max that was high for a man of his age, but consistent with his running performance.    A high VO2 max might be a consequence of training and/or genes.

The fact that he won the M45 world masters 1500m championship in 4:09 at age 45 makes it likely that his VO2max was already relatively high very early in middle-age.  At that stage his training included a substantial number of intense track sessions.  It is therefore unlikely that his VO2max at age 70 can be attributed entirely to the nature of the training and racing that he has done since his late 60’s.

He has maintained this polarised pattern for more than 15 years, apart from several instances in which misadventure or injury have demanded quite long periods of recovery, during which he has re-built training volume slowly.   Whatever the contributions of his genes and the training earlier in his career, the long duration of his current pattern of training and racing does indicate that this current pattern has succeeded in maintaining his extremely high level of performance into his mid-eighties.  It is therefore potentially worthwhile for other elderly distance runners to explore the possibility that it might work for them.

About 18 months ago, I set out to emulate the major features of his training program, aiming for at least three long slow runs each week, gradually increasing the duration from 60 minutes to 120 minutes over a period of 3 months.  As I still work and have limited time available, I was obliged to do two of my long runs on the week-end and therefore had little opportunity for the intense racing that was part of Ed’s program.  I was also aware of the need to avoid placing undue stress on my left knee that had bene damaged in an episode of acute arthritis a few years ago.  I therefore replaced Ed’s intense racing with intense sessions of 30-50 minutes duration on the elliptical cross trainer.

Over a three month period I was able to build up the duration of long runs with no difficulty. I enjoyed not only a clear increase in endurance but also developed a substantial capacity to metabolise fat, most noticeable from my ketotic breath at the end of long training runs.  However the improvement of my aerobic capacity, assessed by calculating beats/Km recorded over similar terrain, was only modest.  I was a little disappointed by this modest gain, and also a little disconcerted by early signs of accumulating fatigue in December.  Nonetheless, I considered that progress at that stage was satisfactory, and was looking forward to a spring marathon.

However a problem that I should have foreseen developed over the winter.  I have long standing asthma that is usually relatively mild, though it is exacerbate by cold air.  I also tend to suffer from various side effects of my asthma medication, and have had little success form changing to different medications.  I therefore need to limit the dose.  Inhaling cold winter air for periods of several hours during my long runs triggered marked constriction of my airways.  To add to this, beginning in mid-December, I suffered a series of quite severe upper respiratory tract infections that exacerbated my breathing difficulties.  I was forced to defer my Whitlock style training until the spring.  By March my fitness had deteriorated quite markedly.  Once again I began the gradual build-up  of long run duration.  Progress was slow, but nonetheless, I set my sights on an autumn marathon.

During a long run with my marathon running sister-in-law, Mary, in the Border District of Scotland in April

During a long run in the Borders District of Scotland in April with my marathon running sister-in-law, Mary, who took the photos


Like Ed Whitlock in training, I adopted a short stride and high cadence to minimise impact damage to my legs.

Like Ed Whitlock in training, I adopted a short stride and high cadence to minimise impact damage to my legs.

Then in July disaster struck.  I suffered quite a nasty all from my bicycle when the front wheel got stuck in tram–tracks that I need to cross at an oblique angle on my daily commute to work. I hit the ground very hard, producing spectacular bruising at every protruding point on the right hand side of by body from knee to forehead.  For several weeks, one side of my face was stained, at first purple and then yellow, along the path where a broad tide of blood had tracked beneath the skin.  The initial concern of the two nurses who rushed to my aid at the scene of the fall had been the possibility of serious head injury, but in the longer term, after the bruises had faded, it turned out that the most troublesome injuries were to my left knee and right elbow.     I had torn lateral ligaments of my left knee, and also damaged the attachment of tendons at my right elbow.  Even now, five months later, both of these injuries limit my movements.  The physio anticipates it will be a year before the knee has recovered.

For several months I could not run at all, but over the past two months I have been cautiously rebuilding once again. In recent weeks I have increased the length of my ‘longish’ runs up to 10Km.  The most dismaying feature is that I cannot cope with paces any faster than 10 minutes/mile.  While the crucial limitation is the knee, I am also appalled by how unfit I have become.    I remind  myself that Ed Whitlock has on several occasions taken almost year to get back to fitness after an injury.   In fact Ed has scarcely raced at all this year, subsequent to an upper thigh/ groin injury that he suffered last year.   For two successive years he has missed the Toronto Waterfront Marathon – an event in which he had set a single age world record on six occasions during the preceding decade. However, despite failing to be on the starting line for this year’s marathon, he did set an M84 single age 10K World Record of 49:08 in the Longboat Island Race in September.

I have no expectation of setting any records, but I fear that even after making generous allowance for the expected slow recovery from my illness last winter and my injury in the summer, I am suffering an alarming deterioration in my overall physical condition.  I suspect that I do not have good genes for longevity. In my next post I will examine the evidence regarding genes for healthy aging.

But whatever my prospects for the longer term future, I am now focused on rebuilding my endurance.  Despite the limited evidence that a Whitlock style program is the best way for me to build aerobic fitness, my experience so far does indicate that it is a good way to build endurance.  As this is my immediate goal, I am again using a modest version of a Whitlock style program.   At present, three runs per week, each of an hour in duration, is about all my body can cope with.  Promoting recovery of my knee ligaments and also vigilant deployment of my inhaler to minimise the constriction of my airways during winter training runs will be equally high priorities. I will not set any marathon target for the near future.   I am playing with the idea of setting targets for a ’heptathlon’ of physical activities, including not only running but also some other challenges to be completed in the week of my seventieth birthday in March.   I will defer specifying the specific targets until I establish how my recovery progresses in December.

The dream of capturing the force of gravity for forward propulsion: re-incarnations of Pose

November 15, 2015

The beguiling dream of capturing the force of gravity to assist forward motion when running has re-emerged in recent months.  There have been two recent re-incarnations of the dream.  Both attempt to overcome the problems of the Pose technique that had attracted enthusiastic followers but also critical analysis in the past decade.   I discussed the benefits and problems of Pose in some detail on this site five years ago.   The more recent versions avoid the unrealistic claim implicit in the Pose mantra ‘Pose, Fall, Pull’ that the Centre of Mass (COM) actually falls between mid-stance and lift-off from stance.  This claim is simply contrary the evidence that the COM rises after mid-stance.  This rise can easily be observed in video recordings of elite and recreational runners.   Both of the recent versions of the theory accept this.

Nonetheless in common with Pose, the recent versions are both based on the argument  that when the COM is ahead of the point of support in late stance, there is a torque acting on the body that tends to produce head-forwards and downwards  rotation.  Unfortunately neither of the new versions adequately addresses the fact than an oppositely direct torque acts prior to mid-stance, and both under-estimate the importance of the push that is required to overcome the braking that occurred during early stance and to get airborne.

Although both theories are flawed and neither provides grounds for claiming that gravity provides energy for forward propulsion, both provide a pointer to  cues which might perhaps help a runner improve efficiency and decrease risk of injury.   It is therefore potentially worthwhile to examine them in greater detail. However, if you are more interested in the practical conclusions than the detail, you can skip to the final section

Kanstad’s Model

Svein Kanstad a Norwegian coach has teamed up with an academic physiologist, Aulikki Kononoff, from University of Kuitpo in Finland to test and publish a creative new version of the hypothesis that gravitational torque acting after mid- stance can drive horizontal motion.  As in the theory of Pose, they argue that due to the forward inclination of the body after mid-stance, there is a component of gravity that drives a head forward and down rotation, as illustrated in Figure 1.

Figure 1. Forces acting after Mid-Stance. GRF = Ground Reaction Force. Force C1 directed along the line of action of GRF propels the body forward and upward. Force C2, at right angle to GRF produces a torque which promotes head-forwards rotation around the point of support

Figure 1. Forces acting after Mid-Stance. vGRF = vertical Ground Reaction Force; hGRF= horizontal Ground Reaction Force.  Force C1 directed along the line of action of total GRF propels the body forward and upward. Force C2, at right angle to GRF produces a torque which promotes head-forwards rotation around the point of support.  Illustrative numerical values are based on the model I presented on this site in 2012

Kanstad’s theory is somewhat more sophisticated than Pose theory, insofar as he recognises that the leg extends during late stance so that there is no net fall of the centre of mass after mid-stance. Because of the leg extension, the situation is a little more complex than portrayed in figure 2 of their paper, which depicts a body rotating about a fixed point of support, with fixed length from point of support to COM.  In reality, the distance from point of support to COM increases as the leg extends, thereby changing the moment of inertias (i.e. the body’s resistance to rotation) and furthermore, the point of support moves forwards in late stance.  Nonetheless as discussed in the extensive comments section of my article ‘Running: a Dance with the Devil’, computation based on a reasonably realistic model confirms that angular rotation in a head-forwards direction does occur after mid-stance.

Kanstad and Kononoff accept that both energy and angular momentum must be conserved, in accord with the laws of physics.  They argue that the angular momentum imparted in late stance is preserved during the airborne phase and then converted to forward linear motion at the next footfall, analogous to the manner in top-spin imparted to a tennis ball causes the ball to accelerate forwards as it rebounds off the ground.

In other words, instead of simply claiming that gravitational energy is captured by falling after mid-stance, they argue that gravity generates angular momentum as the body rises, and the associated head-forwards rotation of the body is converted to forward linear motion at the next footfall.

There are two flaws in their argument.   First of all, while they state that the rotational motion imparted after mid-stance might provide propulsive power at the next footfall, they do not address the question of where the energy associated with this rotation comes from.  It has certainly not been provided by gravity because the body actually rises after mid-stance.  Gravity extracts kinetic energy from the body during this phase. When averaged over the entire gait cycle, the net contribution from gravity is zero.

The energy associated with the rotation imparted during late stance comes largely from a redistribution of the kinetic energy existing at mid-stance.   A small fraction of the energy associated with forward motion of the body is transferred to the rotation.   Rotation acts as a temporary store of energy derived from an energy source other than gravity.

With regard to determining the energy requirement of running, the re-redistribution of energy within the three interchangeable energy pools (kinetic, gravitational and elastic) does not result in any net increase in total energy over the gait cycle.  There is however a loss of energy from these three pools due to several processes that dissipate energy.  There is loss due to friction within the tissues of the body; loss due to air resistance; loss to due to failure to capture all of impact energy at footfall and loss of energy due to the braking that occurs during early stance.   When running at constant speed, these losses are made-up by active contraction of muscles that consumes metabolic energy.  Any suggestion that rotational energy derived from gravity might be a source of propulsive power is false.   Muscle contraction must meet the costs, and the key issue in maximizing efficiency of running is minimising the losses.

Kanstad and Kononoff recommend that the runner should land with the foot as nearly under the COM as possible.  They point out that this would decrease the amount of head-backwards rotation that might otherwise detract from the proposed (but illusionary) advantage of head forwards rotation.   However, the second flaw in their argument is a serious under-estimate of the amount by which foot must be ahead of the COM at footfall.

The laws of physics demand that the foot must be placed appreciably ahead of the COM.  Apart from the instant when the COM is directly above the point of support at mid-stance, the COM must be either before or behind the point of support throughout stance.  The line from COM to point of support is angled either  forwards when COM is behind the support producing a braking effect, or backwards when the COM is ahead of the point of support, producing forward and upwards acceleration (as shown in Figure 1).  If there is no net change in pace over the gait cycle, the forward acceleration generated by the push when the COM is ahead of the point of support must be equal to the deceleration due to braking (if we ignore the effect of air resistance).

It would only be possible to abolish braking while landing with the foot under the COM if the duration on stance was zero, but this would require an infinite vertical ground reaction force. If there is to be no net generation of momentum in an vertical direction averaged over the gait cycle, the upwards impulse generated by upwards ground reaction force (GRF)  during stance must equal the body weight which acts downwards over the entire gait cycle.   Thus the average value of vertical GRF is body weight divided by proportion of the gait cycle on stance and this approaches infinity as duration on stance approaches zero.  Therefore the foot must be on stance for an appreciable time.  While on stance there must be appreciable but equal amounts of acceleration and deceleration.  The deceleration occurs when the point of support is ahead of  the COM between footfall and mid-stance.  Therefore, the foot must land an appreciable distance in front of the COM.

Where should the foot land?

Although the issue of rotation is of trivial importance, the question of where the foot lands is actually of vital importance because it determines braking costs.  It therefore warrants careful consideration.  While the forward acceleration generated when the COM is ahead of the point of support must equal the deceleration occurring when the COM is behind, the proportion of stance time spent with the COM ahead of the point of support is not necessarily equal to the proportion when COM is behind the point of support, because the cumulative effect of acceleration or deceleration are determined by both duration and magnitude of the force. The force tends to be greater in early stance because there is substantial tension in the leg at footfall to prevent the knee buckling.  Force plate data confirms the rapid rise in ground reaction force immediately after footfall.  As a result, the duration between footfall and mid-stance is less than that between mid-stance and lift off, even though the net transfer of linear momentum over the gait cycle is zero when running at a steady pace.

Observation confirms these theoretical predictions. For example Cavagna and colleagues reported measurements of the braking time and the acceleration time during stance in sample of 10 runners at various speeds.  At 10 Km/hour (2.8 m/sec) the average braking time was 0.125 sec and the acceleration time was .145 sec.  From these numbers it can easily be shown that on average the COM advanced 35 cm from footfall to mid-stance (i.e. the COM was approximately 35 cm  behind the point of support at footfall) and at lift-off it was  40 cm ahead of the point of support. (Note that to be precise we need to know how much the point of support moved forwards during stance but allowing a small movement of the point of support would make only a small change in these estimates of distance travelled during braking and acceleration.)

Cavagna  also reported that the difference between braking time and acceleration time diminished as speed increased.  This is almost certainly because at greater speed it is necessary to exert a stronger push against the ground after mid-stance, thereby reducing the difference between forces exerted during braking and acceleration phases.  Cavagna reported that braking time and acceleration time were equal at paces above 15Km/hour.    At 15Km/hour (4.15 m/sec) braking time and acceleration time were both 0.1sec. Thus the COM advanced by 41.5 cm in each half of the stance period.

However Cavagna provided no indication of the competence of these runners.    His runners did not necessarily achieve optimal placement of the foot. Would they have been more efficient if the foot had landed less far in front of the COM leading to a shorter time on stance and less braking?

The key question is: what is the optimum time on stance? It is necessary to bear in mind that while less time on stance decreases braking costs, the need for a relatively longer airborne time demands a more powerful push, creating not only greater stress on the legs but also greater loss of energy at impact, as only about 50% of impact energy can be captured as elastic energy, so an extremely short time on stance is likely to be inefficient.

In the study of Weyand, in which nine of the 10 runners studied were competitive athletes, all except one of the 10 spent appreciably less time on stance, at comparable paces, than the average runner in the study by Cavagna.  As they approached their top speed, all of Weyand’s runners decreased time on stance towards a limit of 0.1 sec (total for both acceleration and deceleration).   It is possible that 0.1 sec on stance is the optimum duration for efficient capture of impact energy as elastic energy.

The shorter stance times achieved by the runners studied by Weyand suggest that on average Cavagna’s runners spent too long on stance for optimum efficiency.  Possibly they simply lacked the power to get airborne, but it is also possible that a mental focus on landing with the foot more nearly under the body might have helped reduce stance time.  While the recommendation of Kanstad and Kononoff  (and many other coaches) to land with the foot as nearly under the COM as possible is advice to aim for something impossible, it is nonetheless is likely to be a useful cue for runners who tend to spend too long on stance.

The Virtual Pivot Point Model

The second these recent versions of the ‘gravitational torque’ theory  is the Virtual Pivot Point (VPP) model described by Mick Wilson in a post on 15th Oct 2015. on Lee Saxby’s  ‘Born To Run’ web- site.   Mick Wilson is a Senior Lecturer in the Department of Sport and Exercise Sciences at Northumbria University

A key feature of the VPP model is that the tension in the muscles of the trunk, especially the hip extensors and flexors is adjusted to ensure that the ground reaction force is directed along a line joining the point of contact of foot with the ground to a fixed point (the VPP) high in the runners torso (Figure 2).   During early stance, when the point of support is ahead of the VPP the direction of action of GRF is upwards and backward.  The torso is tilted forwards a little due to the momentum of the torso when the forward movement of the foot is arrested. The hip extensors act to prevent buckling at the hip.  By late stance the direction of action of GRF is upwards and forwards.  The torso now tends to incline backwards relative to the thigh and the hip flexors contract to resist this. The action of hip extensors in early stance and flexors in late stance stabilises the body, preventing it buckling at the hip, and keeping it upright.  It is reasonable to propose that these actions of hip extensors and flexors play a cardinal role in keeping the body upright.

Figure 2. The Virtual Pivot Point Model. The combination of gravity and GRF results in a force acting along the line of GRF and a component at right angles to GRF which exerts a rotational effect. VPP = Virtual pivot point; COM = Centre of Mass; GRF = Ground Reaction Force. In early stance, the force aligned with GRF arrests the descent of the body and also has a braking effect, while the ‘rotational’ component at right angles to GRF creates a head-backwards rotation. In late stance, the force aligned with GRF propels the body upwards and forwards, while the ‘rotational’ component at right angles to GRF creates a head-forwards rotation.

Figure 2. The Virtual Pivot Point Model. The combination of gravity and GRF results in a force acting along the line of GRF and a component at right angles to GRF which exerts a rotational effect. VPP = Virtual pivot point; COM = Centre of Mass; GRF = Ground Reaction Force.
In early stance, the force aligned with GRF arrests the descent of the body and also has a braking effect, while the ‘rotational’ component at right angles to GRF creates a head-backwards rotation.
In late stance, the force aligned with GRF propels the body upwards and forwards, while the ‘rotational’ component at right angles to GRF creates a head-forwards rotation.

Furthermore, the variation of inclination of torso relative to hips from a slight forward lean in early stances results in the direction of action of GRF passing forwards of the COM to pass through the VPP, in early stance, while it passes behind the COM in late stance to the same pivot point in upper torso in late stance.  Although in the VPP model the line of action of GRF does not pass through the COM (as was assumed by Kanstad and Kononoff), the direction of action of GRF is nonetheless upwards and forwards in late stance.  As in the Kanstad model (and also in the Pose model) there is a torque that tends to produce acceleration in ahead forward and down direction during later stance.  Similarly, an oppositely directed rotation will be generated when the COM is behind the points of support in early stance. The main difference between the models is that at any particular point in time after mid-stance, the inclination of GRF is a little less forwards that would be the case in the Kanstad and Pose models.

Unlike Kanstad, Wilson makes no attempt to explain how this rotation might be converted to forward motion.  Furthermore, Wilson does not specifically claim that the head forward rotation induced after mid-stances exceeds the head-backward rotation induced before mid-stance.   However these limitations do not matter, because, as in the Kanstad model, gravity can provide no additional energy while the COM rises after mid-stance.  The energy associated with any rotation generated by gravitational torque after mid-stance is largely derived by redistribution of the energy in the pool of kinetic and elastic energy existing at mid-stance.  There is one slight difference.   In the VPP model, the direction of action of GRF is long a line that passes behind the COM.  If this is in fact the case, the active contraction of muscles responsible for generating GRF will contribute directly to the energy associated with rotation.     But gravity does not contribute.

Another misleading feature of Wilson’s account of the VPP model is his claim that the forwards and upwards GRF is generated purely by elastic recoil, so that an active push is not necessary.  This could only be the case if the kinetic energy associated with downward movement at footfall could be captured as elastic energy and subsequently released with 100% efficiency.  In fact, only about 50% of the kinetic energy of downwards motion at footfall can be recovered.  Although Wilson acknowledges the fact that the COM rises after mid-stance, he actually appears to deny that any active muscle contraction is required to generate GRF.  Thus he very seriously underestimates the work that must be done when running.  But could this under-estimate be a virtue? This question leads us to the issue of what useful lessons might be learned from these two recent versions of the gravitational torque theory.

What useful practical lessons might be learned?

Why does the claim that gravity provides forward propulsion continue to attract attention?  Many recreational athletes appear to benefit from the mental image created by the notion that gravity provides forward propulsion.  As mentioned in my discussion of the theory of Kanstad and Knononoff, at least part of the benefit comes from the encouragement to land as nearly under the COM as possible.  Although impossible to achieve, this advice discourages over-striding and tends to promote a short time on stance.   However, the advice to land nearly under the COM is not specific to theories claiming that gravity provides forward propulsion.

In a more subtle way, the illusion that gravity might provide propulsive power tends to discourage a conscious focus on pushing against the ground.   A short time on stance is only possible if there is a strong push, but perhaps paradoxically, for most athletes, conscious focus on the push is counter-productive.   It is likely to lead to delay on stance – the opposite of what is required.  Effective push-off from stance requires precise timing.   For most runners, this precision is best achieved automatically.   A cue that minimises potentially harmful conscious interference with the precision of  timing is likely to be beneficial.

While a cue that promotes an automatic rapid lift off from stance is likely to be beneficial, I would prefer to employ a cue that are based on sound science rather than one based on illusionary theory.   One consequence of spending a short time on stance is a relatively long airborne time associated with a relatively large amount of flexion and hip and knee of the swinging leg.   I find that conscious focus on the swing rather than the push can be the most effective way to minimise harmful conscious interference with the precision of timing of the push.

The focus on an upward and forward swing of the thigh should be combined with a focus on a sharp swing of the arm in a downwards and backward direction.  Our brains are wired to produce coordinated oppositely directed movements of the leg and arm.  Because the brain can apply more finely tuned control of our arms and hands than to our legs and feet, more precise control can be achieved by placing the main focus on the arm swing.  Precision in timing of the flexion of the hip is necessary to ensure that the swing does not lead to over-striding .

The required mental image of the swing is cultivated by the swing drill. However the swing drill does not involve getting airborne and hence does not help develop the association of a conscious swing with a forceful non-conscious push of the stance leg.   For this, I find the Pose Change of Support (CoS) drill is effective.   This drill entails alternating shift of stance from one leg to the other without forward motion.  The mental focus is on a precise flexion of knee and hip of the leg that is relinquishing the role of supporting the body; not on driving the other leg downwards.

Although CoS is a Pose drill, you do not have to invest faith in the claim that gravity provides forward propulsion to benefit from it. In fact CoS is similar to the major form of the ‘Hundred Up’ drill developed by WG George, the world’s fastest miler in the nineteenth century.   In contrast to Pose CoS, the ‘Hundred Up’ places emphasis on flexion of the hip to bring the knee to the level of the hip. This makes the drill quite effortful, but I do not think it is essential to lift the knee to hip height.  The greatest focus should be on precise timing.  George did place emphasis on the well-controlled swing of the arms, which helps promote precise timing, though I recommend raising the arm higher and closer to the chest during the forward arm swing than is depicted in George’s model (Figure 3) as I believe a higher arm action promotes better control of the swinging leg and minimises risk of over-striding.

Figure 3: Illustration from hundredup.com

Figure 3: By courtesy of hundredup.com

In conclusion, in my opinion Pose and its more recent re-incarnations encourage a helpful focus on an effective swing without over-striding, while minimising the risk of harmful conscious interference in the essential push.  I do not consider that it is necessary to invest faith in an illusory horizontal propulsive effect of gravity in order to achieve this helpful focus on the swing.

How much does this matter during every day running? For an athlete who suffers repeated injury, careful analysis of running form to identify possible errors is crucial and conscious focus on cues promoting good style is an essential part of correcting errors.   Even when not dealing with injury, I think it is worthwhile to consciously attend to form during at least a small portion of each training session.  During long races, conscious focus on a precise and firm downwards and backwards swing of the arm at lift-off from stance can play an important part in preventing a loss of power when tiredness builds up. I recommend including a short period of the CoS drill, together with conscious attention to arm action, in the warm-up to all training sessions.

Cadence, stride length and Mo Farah’s finishing kick

September 5, 2015

To run faster you need to increase cadence, stride length or both.  The question of which it is best to increase is not easy to answer. In particular, the question of the optimum cadence has long been an issue of discussion among runners and coaches.

On the basis of observations of athletes racing distances ranging from 800 m to marathon at the Los  Angeles  Olympics in 1984, Jack Daniels suggested that across various distances, cadence should be at least 180 steps per minute.  The figure 180 became enshrined in folklore.  There have been two niggling concerns about this. First, many recreational athletes tend to adopt a slower cadence.  Secondly, it is clear that among both recreational runners and elites, cadence tends to increase with pace.  For example, observation of a video recordings of 5000 m races reveals that many elite athletes increase cadence to 200 steps/min or more in the final lap.

Consideration of  the effect of increasing cadence on the peak height of the centre of gravity during the airborne phase illustrates why a fairly high cadence is beneficial from the point of view of both efficiency and minimizing risk of injury.

First, we need to consider the question of what proportion of the gait cycle should be spent airborne. Much empirical evidence indicates as speed increases, a shorter time is spent of stance.  For example in his study of the factors influencing running speed, Peter Weyand found that the proportion of gait cycle spent on stance typically decreased by around 40% as speed increased from 3 m/sec to 8 m/sec.  This is understandable as the shorter the time on stance, the less the braking.  To minimize braking at high speed, at least half of the gait cycle should spent airborne.

However when airborne, after mid-flight, the  body inevitably accelerates downwards under the influence of gravity.  The total vertical distance fallen in one long hop is greater than the fall in a series of short hops of equal total duration because the body accelerates to a greater average speed in a longer fall.  As a result, the total gain in height and the energy that must be spent on getting airborne increases with increases of step duration.  In addition, the impact forces are greater the longer the step duration.  Conversely higher cadence and shorter step duration result in lesser expenditure of energy on getting airborne and lesser impact forces.

However, the saving in cost of getting airborne must be set against the increased cost in repositioning the legs, The swing leg must overtake the torso before footfall, and the cost of accelerating the swing leg increases in proportion to the product of cadence and speed (see calculations in the side bar).  The need to avoid large repositioning costs sets an upper limit to cadence. The most efficient cadence is that which minimizes the total cost of getting airborne; overcoming braking; and repositioning the legs.

However, self-selected cadence differs  greatly between individuals. Recreational runners tend to have relatively low cadence, often less than the 180 recommended by folk-lore.  A study of recreational runners  by Heiderscheit and colleagues  demonstrated that a typical recreational runner might decrease both airborne costs and braking costs by increasing the self-selected cadence by up to 10% .  Heiderscheit reported that at a pace around 3 m/sec, a 10% increase in step rate from a self-selected mean step rate of around 170 resulted in a reduction of approximately  20%  in energy absorbed at hip, knee and ankle joints., It is likely than many recreational runners would  benefit by increasing cadence.

Elite 5000 m runners

Even elites differ greatly, with typical cadence during the mid-stages of a 5000 m ranging from 180 to over 200 steps/min.  Why is there such a large range of cadence among elites? I suspect it is largely determined by the efficiency with which the athlete can capture the energy of impact at footfall as elastic energy and use it to help get airborne again.  An athlete who can achieve a greater saving through elastic recoil will require less energy to get airborne and therefore can afford a lower cadence and longer stride at a given pace.  If such an athlete can increase cadence while maintaining his/her long stride in the final lap of  a 5000m, he/she will have an awe-inspiring  powerful finishing kick.

The best illustration of this is provided by Mo Farah.  In a previous blog post, I discussed Mo’s cadence during the indoor meeting in Glasgow in 2009, when he set a British indoor 3000 m record.  In the middle stages of the race, his cadence was around 175.  For example, he covered the sixth lap of the 200 m track at a pace of 6.4 m/sec with a cadence of 175 steps / min and a step length of 2.18 m.    He made his decisive break from the field in 13th lap, by increasing pace to 6.6 m/sec. He achieved this by increasing his cadence to 185 steps / min while his step length remained virtually unchanged at 2.17 m.

It was interesting to contrast his long-loping style with that of Galen Rupp as they ran together in the middle of the pack, with Galen about metre behind Mo, along the back-straight in eighth lap of the 5000 m in the London Olympics in 2012.  Mo’s cadence was 190 steps/min while Galen’s was 204 steps/min.  In the fiercely contested final lap Galen was dropped as Mo increased his cadence to 208 steps per minute while maintaining  a step length of 2.18 m to hold off six strong contenders.

In the World Championships in Beijing in 2015, again it was Mo’s ability to maintain his long stride while increasing cadence that carried him 8 metres clear of Caleb Ndiku in the home straight.   Mo’s cadence of 204 steps per minute was only  marginally faster than Ndiku’s 202 steps per minute, but the telling difference was Mo’s step length of 2.24,m  compared with Ndiku’s 2.08 m.

The secret of Mo’s powerful finishing kick is his ability to maintain his long stride as he increases cadence to match that of his opponents in the final lap.   It is most likely that this is based on very effective elastic recoil allowing him to re-use impact energy to get airborne.  It is noteworthy that he had this ability in 2009, before he joined Alberto Salazar’s training group in Oregon. It is probable that the discipline of Alberto’s coaching took him from the status of UK record holder to World Champion, but the foundation for his later achievement had clearly been laid before 2009.  It is an intriguing question to wonder how much of this reflects his genetic endowment and how much reflects the trainable features of his running style.

At footfall, his right foot splays outwards in an ungainly manner, but perhaps more relevant, to my eye, he typically exhibits about 10 degrees of dorsiflexion of his ankle immediately prior to foot-strike.  This is clearly illustrated by contrasting the orientation of Mo and Galen’s feet an instant before footfall as they run lock-step (though with Mo landing on the left while Galen is on the right) along the back straight at 9:05 in the 5000m at London, 2012, captured in  Michael Wilson’s slow motion video.   This small degree of dorsiflexion will pre-tension Mo’s Achilles and promote efficient capture of elastic energy.

Neuromuscular coordination for distance running

July 30, 2015

It is well established that countermove jump height (CMJ) is a good predictor of sprinting speed.  This is not surprising because CMJ performance depends on powerful type 2 muscle fibres and on the ability to coordinate the recruitment of these fibres.  In the CMJ, flexion of the hips and knees produces eccentric contraction of the corresponding extensors immediately prior to the explosive concentric contraction that propels the body upwards.  It is necessary to recruit the muscle fibres in a manner that harnesses the enhancement of power generated by the eccentric contraction.

The relationship between CMJ performance and distance running performance has been less thoroughly investigated.

In assessing endurance training, aerobic capacity and lactate threshold have been the main foci of attention, but other training-related variables also predict performance.  It is has been demonstrated that difference between elite athletes in volume of zone 1 training (comfortably below LT) predicts distance race performance (e.g. 10Km). In addition, it is fairly well established that a high values of the ‘stress hormone’ cortisol sustained across a period of months predicts poorer performance.

However, somewhat paradoxically, within an individual athlete, week to week variations in training volume and cortisol values make the opposite predictions.  In a study comparing seasons best and seasons worst performance in elite athletes, total training volume  was less but volume of zone 3 training  (appreciably above LT)  was greater in the week before the seasons best performance. Cortisol tended to be higher a week before the best performance, Countermove jump height was also higher in the week before the best performance.

This apparent paradox is consistent with the evidence that a taper should involve decrease volume but not a decrease in training intensity.  The fact that CMJ was higher before the season’s best performance suggest to me that zone 3 training in the week preceding the event promotes good neuromuscular coordination.

The importance of neuromuscular coordination is clearly illustrated by the clunkiness that triathletes experience during the bike to run transition.   The rapid gains in weight lifting performance  at the beginning of a lifting program are most likely due to improved recruitment of muscle fibres.  Conversely, fatigue impairs neuromuscular coordination, and measurement of postural sway has been proposed as a sensitive measure of impaired neuromuscular coordination arising from fatigue in footballers.

Overall, the evidence indicates that neuromuscular coordination is crucial for both athletic performance and injury minimization but it is rarely the focus of attention in endurance training.  While not a specific focus of attention, when we engage in routine warm up we do in fact achieve  short-term enhancement of neuromuscular coordination, and when we accumulate miles of training, we engage in long-term enhancement of neuromuscular coordination, but we rarely think of these activities as exercises in enhancing neuromuscular  coordination.  However, we are more likely to produce effective enhancement of  neuromuscular coordination if we plan our warm-up and training activities bearing neuromuscular coordination in mind.

The elements of coordination

Recruitment of the optimal number and type of muscle fibres:  because much of our training should be at an intensity less than racing intensity, we need pay attention to the need to ensure that we do retain the ability to recruit type 2 fibres as effectively as required at race pace.  Although the importance specificity in training is sometimes over-rated, at least some specificity is essential.  As discussed in my recent post on lactate shuttling, beneficial enhancement of the ability to handle the accumulation of the lactate can be achieved by a large volume of low intensity training.  However the danger of a program focussed too strongly on low intensity running is the development of a tendency to plod slowly under all circumstances.    It is therefore crucial to do at least some training at or near race pace, especially when fatigued as is likely to be the situation in the later stages of a race.  Progressive runs that achieve a pace at or even a little faster than race pace are likely to be beneficial

Recruitment of muscles in the optimal sequence:  The action of running entails a very complex combination of muscle contractions, requiring that the extensors and flexors at each of the major joints of the leg are recruited in a precisely timed sequence.

Speed of recruitment of muscle fibres:    With increasing age, deterioration in running speed is associated with loss of stride length; not cadence.    This is accompanied by a atrophy of muscles and loss of strength.  However as I found three years ago when engaged in  intense high-load weight lifting program for several months, I was able to increase my strength to the point where I could squat a heavier load than Mo Farah, but  my stride length did not increase appreciably, and my speed remained but a very pale shadow of Mo’s speed.    Speed depends on  power: the ability to exert force rapidly.  This requires effective, rapid recruitment of muscle fibres.  It is far harder to train power than speed, though there is some evidence that focussing on a rapid contraction during the concentric phase of a lift, at moderate load, can produce a worthwhile gain in power.

Implications for warming up For most of my training sessions, I employ a warm up procedure that includes 10 activities, beginning with simple movements designed to get all of the major joints  of the leg moving freely, and proceeds though a sequence in which  power output gradually increases.

Calf raises

Hip swings, (straight front to back; rotating from foot behind to opposite side in front.)

Body-weight  squats (aiming for hips below knees)

Single leg squats

Lunge, to front and side

High knees

High knees skipping

Hopping (fast, small hops)


Surges at race pace

Time for each is adjusted according to how my body is reacting, though typically each of the first 8 activities takes 20-60 seconds; the focus is on fluent action rather than effort.

Implications for injury minimization Recent studies, reviewed by Herman and colleagues, reveal  that in a variety of different sports, poor neurocognitive performance, either at baseline or in the aftermath of a concussion, is associated with elevated risk of musculoskeletal injury. It is probable that a thorough warm-up that  sharpens up neuromuscular coordination is a good way to minimise risk of injury.

Measuring neuromuscular coordination The CMJ is widely used  in various sports, especially team games such as football, to assess fitness.  However, it has three potential disadvantages as a measure of neuromuscular coordination for the distance runner: 1) it is not a ‘pure’ measure as performance depends on type 2 fibre strength in addition to coordination; 2) maximal performance is quite demanding and creates the risk of injury; 3) accurate measurement requires special equipment.

I have been experimenting with time taken to perform 20 line jumps as a test of coordination.  It does depend on other aspects of fitness such as muscle strength  to at least a small extent, but placing the emphasis on time rather than maximal power focuses attention on coordination rather than strength.  The risk of injury is small. At this stage, the utility of timed line-jump performance as a test remains speculative as I have not tested it systematically.  Typically, I find that my time for 20 line jumps decreases from 9.0 seconds after a few minutes of jogging to 7.5 seconds after the ‘neuromuscular’ warm up described above.  Time for 20 jumps increases dramatically after a long run.  Provided I can establish that the test yields consistent results when assessing deterioration in neuromuscular coordination associated with fatigue, I plan to use it to determine whether or not light weight shoes (Nike Free 3.0) result in greater deterioration in coordination during a long run, compared with more heavily padded shoes.

Conclusion It is almost certainly true that many of the activities that athletes and coaches have traditionally incorporated into warm-up and training achieve their benefit at least partly through enhancing neuromuscular coordination.  However by focussing on the more easily quantifiable physiological variables when planning and assessing training sessions, there is a risk that endurance athletes might fail to optimise training to achieve the required combination of aerobic capacity, strength and coordination.   Perhaps we should place more emphasis on a systematic approach to enhancing neuromuscular coordination during training, and on measuring it to assess the outcome of that training.

The lactate shuttle and endurance training

June 19, 2015

Races from 5000m to marathon are run at a pace that is strongly predicted by pace at lactate threshold because the accumulation of acidity is a major factor limiting muscle performance.  During the combustion of glucose to generate energy, the major source of acid is lactic acid.   Lactic acid is a compound of two ions: negatively charged lactate ions and positively charged hydrogen ions.  Under normal circumstances within the body, lactic acid dissociates into these two constituent parts, lactate and hydrogen ions, and it is the latter that create the acidity.   At least in part, the hydrogen ions are buffered (i.e. mopped-up by  other negative ions within tissue) but once this buffering capacity is saturated, hydrogen ions accumulation creates an acid environment that impairs the efficiency of muscle contraction.

However lactate itself can be used as fuel in various locations in the body, and as it is itself metabolised hydrogen ions are removed.    Thus, understanding the mechanisms by which lactate is transported around the body and the mechanisms by which it is itself metabolised provides the basis for rational planning of training.

The orthodox view

The scientific studies of Louis Pasteur, in the nineteenth and early twentieth century, and subsequently by Hans Krebs, AV Hill and others, early in the twentieth century uncovered the mechanisms of anaerobic and aerobic metabolism of glucose, and established the orthodox view that shaped the theory of training for distance training through the second half of the twentieth century. According to this orthodox view, glucose is initially metabolized by the process of glycolysis, to produce pyruvate,  This anaerobic transformation of glucose to pyuvate releases a modest amount of energy which is transferred into the high energy bonds of the energy-rich molecule, ATP, and ultimately can be used to fuel muscle contraction.  But in the presence of oxygen much more energy can be derived via aerobic metabolism of pyruvate. The pyruvate is transported into mitochondria and converted to acetyl-CoA by an enzyme complex known as the pyruvate dehydrogenase complex.  Acetyl-CoA then undergoes a series of chemical transformations catalysed by the aerobic enzymes within mitochondria.  The acetyl group is oxidized to carbon dioxide, releasing a relatively large amount of energy which is incorporated into ATP, thereby providing a substantial enhancement of the supply of energy for muscle contraction.   In contrast, when the rate of delivery of oxygen to muscle is inadequate, muscle contraction must be fueled via the modest energy yielded by conversion of glucose to pyuvate, and the pyruvate is converted to lactate, thereby generating potentially harmful acidity.

The lactate shuttle

The orthodox view is indeed substantially correct, but is misleading because a substantial proportion of pyruvate is converted to lactate even when oxygen supply is adequate to sustain aerobic metabolism in mitochondria.   The way in which the body deals with this lactate is of crucial importance to coaches and athletes.  It was not until the final years of the twentieth century that an adequate understating of the way in which lactate in handled in the body emerged.    The newly emerging understanding was based largely on the work of George Brooks of the University of California, Berkeley Campus, who developed the concept of the lactate shuttle.  Lactate shuttling refers to a group of processes by which lactate is transported within and between cells to locations where is undergoes metabolism.   There is still debate about the details of these mechanisms but the broad principles are now clear, and these principles have major implications for optimum training for distance running.

The first key point is that a proportion of the pyruvate generated in the first stage of glucose metabolism is converted to lactate in the cytosol (the fluid medium inside cells) of muscle fibres, across a very wide range of work-rates, extending from the low aerobic to anaerobic zones.  In the low and mid-aerobic range, the majority of the lactate is transported across various membranes to various different sites where it is metabolized, so there is very little observable accumulation of lactate in blood until the rate of generation of lactate rises near to the limit of the body’s ability to transport and utilize lactate.  Beyond this point, the concentration of lactate and hydrogen ions in blood rises rapidly (the Onset of Blood Lactate Accumulation, OBLA); respiration becomes very effortful, and the ability to maintain that pace is limited by the limited ability to tolerate acidity.

It is helpful to understand the various processes by which lactate is transported out of the cytosol of muscle cells and subsequently metabolized, in order to design a training program that is likely to enhance these processes.

There are four major pathways by which lactate is transported and metabolized:

  • Transport across the outer mitochondrial membrane to a site where lactate dehydrogenase converts lactate back to pyruvate which then undergoes aerobic metabolism within the same muscle cell. This process results in dissipation of lactate and acidity in the cell where it was created and hence is merely a mechanism that ensures that acid does not accumulate when oxygen supply is adequate to sustain aerobic metabolism.
  • Transport out of the muscle fibre where it was created, into nearby fibres where is can be transported across the outer mitochondrial membrane and metabolized. This mechanism makes it possible for lactate to be generated in type 2 muscle fibres, which are powerful but have relatively low aerobic capacity, and then metabolized in type 1 fibres which have high aerobic capacity.  Training ‘at a good aerobic pace’ as advocated by Lydiard is potentially a good strategy for developing this mechanism.  Although the training pace might be comfortably below OBLA, the ability to dissipate lactate and acidity will be enhanced, leading to a an increase in pace at OBLA and improved performance over distances from 1500m to marathon.
  • Transport out of the muscle fibre where it was created into the blood and thence to other organs, such as heart and brain where it can be metabolized to generate energy
  • Transport out of the muscle fibre where it was created into blood and thence to liver where it can be converted back to glucose by the process of gluconeogenesis. This mechanism is likely to help conserve glucose stores in a manner that is useful in long events such as the marathon.

It is important to note that all of these processes entail transport across a membrane or several membranes prior to metabolism.   Transport is an active process that is performed by specialised proteins known as monocarboxylate transporters (MCTs). There are several different type of MCT located in different types of membrane.   Like many proteins in the body, utilization encourages production of increased amounts of the protein.

Aerobic base-building

Low intensity running is not merely about developing the capillaries to deliver blood to muscle and mitochondrial enzymes that perform aerobic metabolism.  Because appreciable amounts of lactate are produced, transported and metabolized even at work-rates well below OBLA, low intensity training  helps build capacity to handle lactate.

Think of the flow of glucose into the energy metabolic pathway as being like water flowing from an inflow pipe into a sink. The inflow pipe is actually the anaerobic pathway (glycolysis).  A pool of interchangeable pyruvate and lactate tends to accumulate in the sink.  There are two ways out of the sink: transport out of the cell or down the plug hole into mitochondria where aerobic metabolism occurs.  In fibres in which the aerobic system has been well developed , the flow down the plughole can accommodate a large flow of glucose into the system without the sink overflowing.  Shuttling from type 2 fibres which have less well developed aerobic capacity, into nearby type 1 fibres also helps maintain the flow.  There is minimal accumulation of acid in either muscle or blood.  So purely aerobic development, which can be achieved by low intensity training, minimizes accumulation of acid at 10K and 5K pace.   Shuttling explains why runners who only do low intensity running during base building nonetheless usually find that 10K and 5K pace improve despite doing no training near race pace.

The important conclusion for the endurance athlete is that low intensity training is an effective way to develop an aerobic base which helps raise lactate threshold.  It enhances performance at all distances for 1500m to ultramarathon.

Interval training and fartlek

Lactate shuttling also provides an explanation for the effectiveness of interval training and fartlek.  A brief intense effort epoch above threshold generates a surge of lactic acid, and is followed by a recovery epoch during which lactic acid levels fall rapidly, before the sequence of effort and recovery is repeated.  Thus, large gradients in lactate concentration develop, resolve and develop again.  It is noteworthy that the drop in lactate during recovery is likely to be facilitated by low intensity running which maintains transport and utilization of lactate during recovery.  A high lactate gradient across a membrane makes high demand on the transport process and is likely to stimulate production of the relevant transporters, the MCTs.

It is plausible that this will be achieved most effectively by ‘cruise’ intervals of the type employed by Emil Zatopek, or by fartlek sessions in which intensity is high enough during the effort epochs to ensure substantial  production of lactate, while intensity during the recovery epochs is adequate to ensure transport and utilization of the lactate produced during the preceding effort epoch


The various pathways by which lactate is transported out of the muscle cells where it is created to locations where it can be usefully metabolized provide a set of mechanisms by which either low intensity training at a pace comfortably below lactate threshold, or by interval training in which lactate is generated in brief surges, can develop  the ability to cope with lactate production at race pace.    Thus training for sustained periods at or near race pace, which tends to be quite demanding by virtue of the sustained stress, has only a relatively limited role to play in training for endurance events.  This might be an explanation for the observation that many elite endurance athletes adopt a polarized approach to training, in which the majority of training is done at a pace comfortably below threshold, together with an appreciable minority of training at higher intensity during interval sessions and  a modest amount of sustained running near to threshold.

Charles Eugster: strength or power?

March 20, 2015

Perhaps the most enigmatic of the trainable capacities required for distance running is efficiency: the ability to generate as much speed as possible from a given amount of energy.  In endurance events, when the vast majority of energy is generated aerobically, it is the ability to extract as much speed as possible from a given rate of oxygen consumption.    Somewhat confusingly, it is usually reported as oxygen consumption required for a given speed and quantified in units of ml/Kg/Km, though this is actually the inverse of efficiency. It is also referred to as economy and is sometimes reported as speed at VO2max. A proportional increase in speed at VO2max will result in a similar proportional increase in speed at sub-maximal rates of energy consumption.

The first focus in planning a training program is on increasing the ability to consume oxygen (VO2max) by increasing blood supply to muscles and increasing mitochondrial enzymes, but for well-trained athletes, the scope for improving VO2max is small.   When generating energy at VO2 max, a substantial amount of metabolism is anaerobic and results in the build-up of lactic acid. Since accumulation of acid limits muscle power output, the second focus of endurance training is reducing lactic acid accumulation, either by increasing the ability to transport lactic acid out of muscle cells and metabolise it in other tissues, such as liver and heart, or by enhancing fat metabolism, which does not generate lactate.   However there is limit to what can be achieved by improving the capacity to minimise lactic acid accumulation.   Once VO2max has been maximised and the accumulation of lactic acid has been minimised, the focus of training must shift to efficiency.

As illustrated by Andrew Jones’ account of the physiological developments achieved by Paula Radcliffe in the decade prior to her phenomenal a marathon time of 2:15:25  in London in 2003, the crucial improvement was in efficiency.  Paula’s VO2max remain approximately constant at around 70 ml/Kg/min over the decade, but her estimated pace at VO2max increased by 15%.  Andrew Jones acknowledged that mechanism by which this increase in efficiency was achieved remains a mystery.

In my recent discussion of this issue, I distinguished between improvement in metabolic efficiency: the amount of work that can be achieved by muscle contraction per unit of energy consumed; and improvement in mechanical efficiency: the pace achieved for a given amount of work by the muscles.   Metabolic efficiency is strongly dependent on the relationship between rate at which muscle fibres shorten during contraction and optimum shortening rate for the type of fibre involved. In general during endurance running, the required of rate of shortening is relatively low. Type 1 fibres are more efficient than type 2 fibres when the rate of contraction is slow.  Therefore, one goal of training is increasing the proportion of work done by type 1 fibres.  This is achieved by low intensity training.  But the need for the powerful contraction provided by type 2 fibres cannot be completely neglected because of their role in achieving mechanical efficiency.

Maximising mechanical efficiency demands optimising the balance between the three major energy costs of running: getting airborne; overcoming braking and repositioning the swinging leg.  The cost of getting airborne can be reduced by spending more time on the ground, but that inevitably increases braking cost.  Braking cost can be reduced by increasing cadence, but the cost of repositioning the swing leg increases with cadence so there is a limit to cadence.   So one cannot escape the need to get airborne – indeed getting airborne is what distinguishes running from walking.  But getting airborne requires a powerful push against the ground.   The force-plate data of Peter Weyand and colleagues indicates that a major determinant of running speed is the ability to exert a strong push to lift off from stance.

For many distance runners, but especially women and elderly men, I think that the most likely factor limiting mechanical efficiency is lack of ability to exert an adequate push.    One of the striking features of Paula Radcliffe’s running in her heyday was her ability to get airborne.   The interesting question is how she developed this ability.  Following her disappointing performance in the 10,000m in Sydney in 2000, her physiotherapist, Gerard Hartmann identified her poor ability to generate the power required to step on and off a high box rapidly.   He recommended a course of plyometrics and weight training.  It is likely that this played a substantial part in her transformation from a leading athlete who was struggling to fulfil her potential into the greatest female marathoner the world has seen.  But was it the plyometrics or the weight training that played the greater part?

Charles Eugster

I was reminded of this question last week when Charles Eugster set a new world record for the MV95 200m in London, with a time of 55.38 seconds.  Like most people, my first reaction was ‘how amazing’ though I was not entirely surprised.  He had done a very entertaining TED talk a few years ago, in which he presented an enchanting picture of a 93 year old with a very positive outlook on life, and a strong message about the virtues of weight training for the elderly.   The story behind his MV95 200m record provokes some interesting speculations about how to improve the ability to get airborne.

Charles was the child of Swiss parents and had spent his childhood in London, before returning to Switzerland.  He had become a dentist despite his parents wish that he become a doctor.  One of his teachers at St Paul’s school had said: ‘Eugster, if I were to put your brain into a sparrow’s head, there would still be room for it to wobble’. He decided that he would be better advised to focus on learning about 32 teeth rather than all the organs of the body.

He had played sport all his life, and in a particular, rowed for his school, but in his eighties, decided that it was time to smarten up his body.  In his TED talk, he says it was all due to vanity. He claimed his ambition is to impress sexy young girls of 70 on the beach.  He had wanted to start on a six pack but his personal trainer, Sylvia Gattiker, former Swiss aerobics champion, said he needed to start with work on his glutes.  She stands no slacking, encouraging him along the lines: ‘…. and breathe out, no, that’s groaning…. breathe out’.

Under Sylvia’s guidance he has developed a spectacular body.  He has won numerous body building and strength awards.  At 89 he became world 80+ Strenflex champion.  Strenflex involves a set of exercises that are scored for form and number of repetitions in a given time.  It is a test of strength, endurance and flexibility.  About two years ago, he took up sprinting, and within less than a year, was British 100m and 200m Masters Athletics 90+ sprint champion.  So his world 200m record last week was amazing but scarcely surprising.

It is nonetheless intriguing to examine his style.

He runs with a high cadence but shuffling gait.  He does get airborne, but not for long.  I suspect this is part because Sylvia’s coaching emphasized reaching forwards with the swing leg, but it is a style quite characteristic of the elderly.   Ed Whitlock, who trained for his 2:54:45 marathon at age 71 by running up to 3 hours per day in a Toronto cemetery, deliberately cultivated as slow shuffle to protect his knees from the pounding during training, but during races, he is a delight to behold: He gets airborne in a manner reminiscent of Paula Radcliffe.

By virtue of his rapid cadence, Charles Eugster reduces both the costs of getting airborne and braking costs, but to my eye, he nonetheless incurs unnecessary braking costs.  His cadence appears is to be near the practicable limit, and any further improvement in efficiency would require spending a smaller proportion of the gait cycle on stance.   His energy cost would almost certainly be less if he got properly airborne, as younger sprinters do.  Impressive as his 200m time of 55.38 seconds is, it is almost certainly limited by a loss of the power required to get airborne.

The elderly lose strength but even more noticeably, they lose power: the ability to exert force rapidly.  It has been recognised for some years that the elderly can regain strength with remarkable effectiveness by lifting heavy weights.  Charles has clearly been very successful in achieving this.  It is noteworthy that in order to become a Strenflex champion, for which it is essential to be able to perform repetitions of various strength exercises rapidly, Charles must have retained some power.  Nonetheless, it appears that in training he has placed his main focus on shifting quite heavy loads, which is not a very effective way of re-building power.

Building power by explosive contractions

There is a substantial body of evidence indicating that the most effective way to build power is to perform muscle contractions  at the rate that maximises power.  Power is the rate of doing work.  Work is the product of force by distance, so power is the product of force generated by distance the load is moved divided by the time taken, or on other words, the product of force by speed of contraction.  Speed of contraction increases as load decreases, and for young adults, peak power is typically generated at about 30% of the maximum force that can be generated:  that is 30% of one repetition maximum  (1RM).   The elderly have less scope for increasing speed of contraction, and maximum power is usually generated at a somewhat great fraction of maximum load.  Typically maximum power is generated at 60% of 1RM.

Because the risk of muscle damage is greatest during eccentric contraction when a muscle is stretched while under load, the safest way to build power is to perform the eccentric phase of the exercise slowly and then execute the concentric phase explosively with maximum  possible speed.  Encouragingly, several recent randomised controlled trials have demonstrated that high velocity power training is feasible, well tolerated, and is effective in increasing leg muscle power in the elderly.    De Vos and colleagues randomly assigned 112 healthy older adults (aged 69 +/- 6 years) to explosive resistance training at one of three intensities (20%; 50%; or 80% of 1RM) for 3 sets of 8 rapid concentric contractions , for 8-12 weeks, or to a non-training control group. Peak power increased significantly by about 15% in all three groups doing the explosive exercises, compared with 3% in the control group.   In comparison with the groups using 20% and 50% of 1RM, the group using 80% of 1RM exhibited a greater increase in strength and also a greater increase in muscle endurance (the number of repetitions that could be performed with a load of 90% of 1RM).  It is also noteworthy that injuries were rare and relatively minor during the explosive sessions.  In fact there were more injuries during the testing of 1RM than during the explosive sessions, suggesting that explosive concentric contractions at moderate load are less risky that slow eccentric contractions at very high load.

Optimising the explosive contraction

The greater increase of strength at higher load reported by de Vos was expected, while the greater endurance at higher load when assessed at 90% 1RM might largely reflect a bias towards maximal recruitment of the type 2 fibres during the endurance test that were maximally recruited during the explosive training.  However the similar gain in maximum power between the three different explosive training loads raises an interesting question about the possibility of biasing the training in favour of type 1 fibres.  At low load, during the eccentric training phase, the type 1 fibres will be preferentially recruited and hence experience gentle pre-tensioning.  During the explosive concentric contraction, it is likely that a wide-range of fibres would be recruited though the bias would usually be towards type 2 fibres.  However, if the type  1 fibres have been pre-tensioned during the eccentric phase, these fibres will tend to show relatively more enhancement of recruitment.  Thus, one might expect a somewhat greater benefit for type 1 fibres at low loads.

During the push off from stance during running (and during squats) much of the load is borne by the extensors of hip, knee and ankle.  Most of the relevant muscles cross two joints, flexing one while extending the other, and hence the fibres undergo a relatively short contraction during the triple extension.   Thus, even during quite fast running, the rate of contraction of the important muscles is relatively slow, and likely to be in the range where type 1 fibres are metabolically more efficient.  This suggests that explosive training with low load might be potentially of greater benefit for endurance athletes.

With regard to the type of exercise most useful for runners, any exercise that produces a triple extension is likely to be beneficial.  While deep squats do produce such an extension, the range of motion is different from that during running, whereas hang cleans require a range more similar to that of running.  However, it is trickier to do hang cleans safely.  It should also be noted that short, steep hill sprints and squat jumps are likely to be effective for increasing power.

The mechanism

The mechanism of the increase in power is not clear.  It is likely that improved fibre recruitment due to enhanced neuromuscular coordination plays a role.   If so, one might expect there to be a ceiling on the benefit that can be obtained over a prolonged period of training.  Nonetheless, on the principle that using a muscle prevents atrophy, there are likely to be long term benefits in ensuring that muscles can be recruited with peak efficiency.

My preliminary experiments

During the past year, during which I have focused more on increasing volume of training than on either strength training or sprinting, I have been dismayed to find that my sprinting speed has decreased yet more than in previous years.   Although I do not yet shuffle quite as noticeably as Charles Eugster (who is a little over a quarter century older than me) I too am forced to increase cadence to a very high level in order to produce speed.

About a year ago I had introduced plyometrics into my routine, but abandoned these as they appeared to be exacerbating the aches in my knees.  I am therefore eager to find a safe way to increase leg muscle power.  I have recently introduced sessions in which I do 3 sets of 8 explosive squats at 60% of 1RM. This has produced no DOMS and in fact leaves me feeling invigorated. I am even experimenting with doing 1 set of explosive squats at moderate load as part of my warm up for running sessions, with the expectation that this will enhance neuromuscular coordination.

It is too early to say whether or not this explosive resistance training has produced a worthwhile increase in ether sprinting speed or in efficiency at sub-maximal paces.  Nonetheless, the impressive gain in strength achieved by Charles Eugster though training with heavy loads has somewhat paradoxically inspired me to try a different approach with the aim not only of increasing strength but also recovering the power to get properly airborne.  But before I allow myself to become too dismissive of the approach employed by Charles Eugster, I should establish that I can run a 200m in 55 sec at age 75, let alone 95.

Endurance Training and Heart Health, Revisited

February 25, 2015

The perennial question of the benefits and risks of running has been back in the news in the past few weeks. First there was the recent publication of another paper adding to the previously reported findings from the Copenhagen heart study. The main conclusion from this long-term study of mortality among runners is that moderate amounts of running increase the probability of a longer life. However, the newspapers seized on the statement that large amounts of running were not statistically safer than a sedentary life-style. That in itself was a trivial conclusion despite its sensational appeal to newspaper editors. The number of people in the sample doing a large amount of exercise was too small to produce statistically robust evidence of either benefit or harm. While mortality rate was higher in those doing a lot of running compared with those doing a modest amount, it was nonetheless lower than in sedentary individuals, but the decrease was not statistically significant. I suspect that the somewhat sensational reporting was at least partly due to the fact that James O’Keefe joined the scientists who conducted the study, to write the paper. I have previously remarked that in my eyes, O’Keefe appears more like a snake-oil merchant than a scientist.

The other publication, a study of adverse cardiac events in over a million British women by Armstrong and colleagues from Oxford, is more measured in its reporting. It too shows that moderate amounts of exercise are beneficial, but those doing a larger amount of exercise had less good outcome than those doing a modest amount (e.g. half and hour three times per week). Nonetheless, even those exercising daily had a better outcome than sedentary individuals.

A third large epidemiological study, the Aerobic Longitudinal Study of 55,137 American adults also revealed that moderate exercise is associated with a substantial reduction in mortality, but yet again those doing a large amount of exercise tended to have higher mortality that those doing moderate exercise. Thus three large epidemiological studies have all demonstrated that moderate exercise is associated with major health benefits, but these benefits are reduced, though not entirely abolished, in those doing a large amount of exercise.  The evidence suggests that in at least some individuals a large amount of exercise is associated with harmful effects on health. This finding is not surprising in light of the very strong evidence from many studies that at least a minority of individuals who do very large amounts of exercise suffer heart damage.

Evidence of heart rhythm disturbances

The best documented adverse effect of extensive amount of endurance training and racing is disturbance of cardiac rhythm, especially atrial fibrillation. A review by Mont and colleagues revealed that long-term endurance athletes have a to 2-10 fold increase in risk of atrial fibrillation.   There is also an increased frequency of potentially more dangerous rhythm disturbances arising in the ventricles. Ventricular rhythm abnormalities are quite common in elderly endurance athletes, and also occur in a substantial minority of young athletes. For example, Verdile and colleagues observed ventricular rhythm abnormality in 367 (7.3%) of 5011 highly trained young athletes with average age 24 without other evidence of heart disease. Six of these individuals underwent successful surgical ablation of the aberrant heart tissue, while 7 with frequent or complex rhythm disturbances who declined surgery were prohibited from competitive sport.   However no adverse cardiac event occurred in any of the 367 young athletes during a follow-up period of average duration 7 years, indicating that at least in young athletes with no other evidence of cardiac abnormality, the arrhythmias are usually benign.

What are the implications for individuals who want to exercise vigorously?

Is there an upper limit to the amount of exercise that is healthy, and if so, what is it? Or can the likelihood of adverse effects on health be reduced by adjusting the way in which we train? There is a twist in the tail of the Oxford study of a million women that throws some light on this. A sub-group analysis revealed that among those who were obese, the women taking a large amount of exercise had a somewhat higher risk of cardiac events than those who exercised only three times a week. However, among those with BMI below 25, those who exercise frequently have a lower risk than those who exercise only three times week.   This suggests that it is not the amount of exercise in itself that does the damage, it is more likely that it is the amount of stress generated by the exercise that matters.    Emerging evidence about the mechanism by which excessive exercise might produce harmful health effects in runners throws a little more light on the issue.

What are the possible mechanisms of damage?

What determines who among endurance athletes is at greatest risk of damage? The mechanism of the damage remains uncertain, but a growing body of evidence provides some clues. Exercise remodels the heart.  The walls of the ventricles become thicker and the cavities become dilated. This is the typical athletes heart. Some athletes also exhibit fibrosis of the muscle. Fibrosis arises when damaged muscle is repaired with a scaffold of fibrous material.  This is a part of the normal mechanism by which inflammation repairs damaged body tissues but can become disruptive if the fibrous deposits become permanent. Fibrosis of heart muscle is likely to disrupt the normal conduction pathways via which electrical signals initiate heart muscle contraction. Although not directly proven, fibrous deposits are a prime suspect for rhythm disturbances.

What causes the damage that sets the scene for fibrosis? Some thought provoking clues come for studies of the effects of strenuous exercise on the right ventricle. The right ventricle has to pump blood through the lungs, and the capillaries in the lungs do not open up as much during exercise as the capillaries in the muscles. Hence, the right ventricle faces a relatively harder task than the left in having to push the increased volume of blood required with less benefit from an accommodating vascular system.  As a result there is demonstrable weakening of the right ventricle that persist for several days after very strenuous exercise. This weakening is associated with markers of transient heart muscle damage, such as increase in levels of cardiac enzymes in the blood stream. For a well trained athlete, the weakening is only appreciable after extremely strenuous exercise. For example, the weakening is only slight after a marathon, though more marked after an ironman, and still detectable a week later. For recreational runners, the damage can be appreciable after a marathon. But perhaps the crucial observation is that the amount of weakening appears to depends on how thoroughly the runners prepared for the marathon. In a study of runners in the Boston marathon in 2004 and 2005, Neilan and colleagues found that appreciable weakening of the right ventricle in those who had done less than 35 miles per week in the preceding moths, but no appreciable weakening in those who had done more than 45 miles per week.

What might convert transient damage into long term damage? In general when body tissues suffer transient damage the repair process includes the construction of a temporary framework of collagen fibres. If there is repeated trauma before full recovery there is greater risk that the temporary fibrous framework will be become permanent. Although there is little direct evidence that this happens in the heart, perhaps the most plausible explanation for the fibrosis observed in the heart muscle of endurance athletes is repeated trauma without opportunity for adequate recovery. Overall the evidence suggests simply that moderate exercise is beneficial for virtually everybody, but if you want to do a lot of exercise you need to build up gradually to avoid over-stressing the body.  Furthermore, it is plausible that demanding training or racing while incompletely recovered from previous strenuous training or racing creates an especially high risk of converting transient damage into long term fibrosis that might act as a precipitant of disturbance of heart rhythm.


Moderate exercise has major health benefits for virtually every one, but a large volume of endurance training diminishes the benefit for some individuals. There is no evidence indicating a fixed upper limit on the amount of exercise that is healthy.   On the other hand, the evidence suggests, but does not prove, that the risks of extensive training are likely to be low if you if you increase training load gradually and avoid demanding training or racing when inadequately recovered.

It is probably no coincidence that what appears to be the safest strategy for avoiding long term damage is similar to the widely accepted recommendation for training to improve performance: increase training load gradually and recover well after strenuous training or racing.

More reminiscences and the science of running injury free

January 5, 2015

The New Year is a time for looking forward, but in the past few days several things have also prompted me to take a backwards glance.   One of these things was the summary of the previous year’s statistics for my blog which Word-press compile each year. Two features intrigued me. First, was the very wide geographic range of the readership.  But even more intriguing was the fact that three of the most viewed pages in 2014 had been posted in 2010 or earlier.   It led me to wonder just how much my views on the topics of those posts have changed in the past five years.

Heart rate variability (HRV)

The most frequently viewed post was one of my 2010 posts on HRV. At that time I was intrigued by the possibility that regular HRV measurement might be an effective way to guide the adjustment of training load. In the preceding years, several studies by Kiviniemi and colleagues from Finland had provided preliminary evidence indicating that daily measurement of HRV was potentially useful for adjusting training load. In particular, a decrease in high frequency HRV was reported to be a useful indicator of the need for recovery. Although several recent studies have confirmed that HRV is related to the effects of training, there are inconsistencies in the findings, and I am not yet convinced that these studies provide compelling evidence that daily measurement provides a reliable basis for day-by-day adjustment of training load. Indeed a recent study by Plews and colleagues reports that daily HRV measurement is only weakly related to training status, though a weekly average was a quite strong predictor of 10K performance.

My own experience is that HRV, measured either at rest or immediately after exercise is not sufficiently consistent to provide a useful guide to adjusting training on a day to day basis. Nonetheless, I do regard a marked reduction in resting high frequency HRV as a pointer towards the need for better recovery when it occurs in association with other signs of stress. Conversely, unusually large amplitude HRV while running appears to be a fairly reliable sign of stress (as illustrated in  figure 3a from my post in 2010). However, the main reason I continue to record R-R traces during training runs is to monitor the frequency of occurrence of rogue rhythms – a common but inadequately understood phenomenon in elderly runners.

fig 3a: Expanded view of HR variability in the period 23 to 25 minutes, before (18 July) and during fatigue (31 August)

fig 3a: Expanded view of HR variability in the period 23 to 25 minutes, before (18 July) and during fatigue (31 August)


The second most frequently viewed post in 2014 was my 2010 discussion of the Dr Romanov’s Pose method of running. That post had drawn many comments at the time of the original posting and has attracted many thousands of views since 2010. Although I started the post with a list of the positive features of Pose, the main message was that Dr Romanov had seriously under-estimated ground reaction force (GRF) during running and as a result had drawn the erroneous conclusion that the net force acting on the runner’s body after mid-stance is directed forward and downwards. This led him to the erroneous conclusion that the centre of gravity falls after mid-stance. In contrast, a realistic estimate of GRF indicates that the net force after mid-stance is directed forwards and upwards. Dr Romanov’s mantra of ‘pose, fall, pull’ does not correspond to what happens. As a result, Dr Romanov seriously underestimates the crucial role of a well-timed push upwards and forwards off stance.

Five years later, I still regard this as the cardinal flaw of the Pose technique. The fact that my post continues to be widely read five years later indicates that the running community is still curious about Pose, but as far as I aware, serious discussion about running technique is now more focussed on how to achieve a well- timed and directed push after mid-stance.  My own opinion is that the most effective strategy is to rely on the cue provided by a brisk downward swing of the arm contralateral to the leg on stance.

Forces acting on a runner after mid-stance.

Forces acting on a runner after mid-stance.

Lydiard v Maffetone

The other ‘historical’ post among the five most viewed in 2014 was my comparison of Lydiard v Maffetone, posted in 2009. I have a great respect for both Lydiard and Maffetone, particularly on account of the emphasis they place on the importance of base-building in the annual training cycle. The purpose of my post was to compare their recommendations for paces during base-building. Lydiard was less precise in his prescription than Maffetone, but as far as can be estimated, both made very similar recommendation for long run pace. However, Maffetone is much more adamant in recommending avoidance of training in the upper aerobic zone during base building. In my post I discussed several of the plausible physiological mechanisms by which running in the upper aerobic zone might be counter-productive, but I concluded that none of the mechanisms was likely to impair aerobic development provided the majority of sessions were lower aerobic sessions. I therefore came down favouring of Lydiard over Maffetone

I still adhere to the main principles that I advocated in that post, though my opinion about optimum paces has changed over the past 5 years. As discussed in my recent post on the virtues of high intensity v high volume training I now favour a somewhat more polarised approach during base-building (and also during race specific preparation) than either Lydiard or Maffetone would have recommended. I think that it is more constructive to replace some of the ½ effort and ¾ effort runs recommended by Lydiard with short high intensity sessions, as I consider that the cost/ benefit ratio of high intensity sessions is greater than that of upper aerobic sessions. However I do not regard this issue as settled beyond doubt.

Candy for Running Nerds

Of all the comments I have received on my blog over the years, the one that most tickled my fancy was Eternal Fury’s remark a few years ago that my blog is a candy shop for running nerds. I assume that the candy to which EF referred was the detailed technical examination of the physics and physiology of running. Indeed I do enjoy looking into the biomechanics and physiology of running.

I believe that the best foundation for making sensible decisions about training and racing is a synthesis of practical observation of what works for others and one’s own experiences, interpreted in the light of what we know about how the body works. So I hope that the candy is both interesting entertainment for running nerds and informative for runners who simply aim to run as ‘fast and injury free’ as possible.

I was therefore very pleased two days ago when Steven Brewer posted a series of questions on my 2012 post ‘Is there a magic running cadence’. It was interesting to review the evidence that I had  presented in 2012, and to note that the evidence that has emerged since then has largely consolidated the picture from 2012. However as the discussion started to become even more arcane, Steven remarked ironically ‘The more I learn, the more I am discovering that running is an extremely complicated process. This makes me appreciate the simplicity of calculating the energy levels of an electron trapped in an infinitely deep well! ‘ At that point, Laurent Therond interjected ‘IMHO, running form is mostly innate, and what your body has come up with is likely to be what works best for you.’

In fact I agree strongly with Laurent. Running is largely innate and therefore we should largely trust our body to run in the manner that comes naturally. However, many runners suffer injury, and when this happens repeatedly we need to ask why.

So is it possible to distil the science of running into a few clear principles?    The short answer is no. Running involves every system of the body, ranging from the brain (and mind) to the toes, so it would be fat too simplistic to try to condense the essentials into a few principles. However, when I started this blog, one of my main pre-occupations was how to run ‘injury free’.   I believe that it is possible to distil the science of running injury free into a small number of basic principles – though as Einstein once remarked, we should seek explanations that are as simple as possible, but no more simple. So here is my response to Steven in which I have tried to distil the science of running injury free, in a manner that is as simple as possible but not too simple.

The distilled science of running ‘injury free’

In the past decade I think there has been an over-emphasis on   faults of style as the major cause of injury. I believe that subjecting the body to greater stress than it can cope with is the major causal factor in in many instances. Therefore one of the main strategies for avoiding injury is building up training load gradually, and at all times recognising when the body is near the limit of coping. This is not easy, though a variety of signs covering both overall well-being (mood; heart rate variables) and focal signs such as accumulating aches in connective tissues or local muscle spasm provide useful clues.

However, in some instances faulty technique plays a role. But there is a great deal of misleading information in circulation, due to over-simplistic analysis. The human body is very complex. Nonetheless, it does obey several well established principles, based on both Newtonian mechanics, and the principles governing the behaviour of biological tissues.

Newtonian mechanics

The first things to consider are the laws of Newtonian mechanics. We need to meet two goals: minimising energy expenditure and minimising stress on body tissues. Minimising energy expenditure requires the optimum adjustment of the three major energy costs: getting airborne; overcoming braking and the cyclical repositioning the limbs relative to the torso. Simplistic focus on just one of these leads to over-emphasis on a single requirement. For example, we can minimise the cost of getting airborne by reducing vertical oscillation, but that inevitably increases the cost of overcoming braking, at a given cadence.   We can minimise both braking costs and cost of getting airborne by increasing cadence, but that increases limb positioning costs.   Conversely, if cadence is too slow there is a strong temptation to increase stride length by reaching out with the swinging leg, thereby incurring braking costs that are inefficient and potentially damaging.

The need to balance the three main costs leads to 2 important conclusions: first, simplistic rules such as avoid vertical oscillation without considering other costs are misleading and potentially dangerous. In general, it is best to let the non-conscious brain do the calculation required to optimise the three energy costs, because the brain is usually very good at finding the most efficient solution.

However, as discussed in most post on running cadence, there appears to be one exception: most recreational runners select a cadence which appears to be slower than optimal for fast running. Maybe this is because we are naturally adapted for slow running over rough terrain where maintaining balance is a high priority; alternatively it might be that a sedentary lifestyle encourages our brains to be too cautious. So if there is one simple issue we should address consciously, it is making sure that cadence is not too slow (eg at least 180 steps/minute at 4 m/sec).

The second general conclusion arising from the need to balance the three costs, is that large forces will necessarily be exerted. A quite strong push against the ground is inevitable. Running is a dance with the devil – gravity. We therefore must build up the strength to cope with this, by gradual increase in training volume. Specific exercises, both plyometrics and resistance exercises, can help.

Associated with the large forces required to get airborne is the fact that the geometry of our hips knees and ankles results in quite large rotational effects around two, or sometimes all three axes, at these joints. Some of these effects are not easily envisaged, so there are certain injuries that do require a careful biomechanical analysis. Nonetheless I consider that gradual build-up of training load and trusting your non-conscious brain is the most effective way of minimising the risk of such problems. If you do decide that you need to adjust style consciously, it is safest to focus on a compact, brisk but relaxed arm action.   This tends to promote a compact efficient leg action as a consequence of the way the brain codes movement.

The physiology of injury

With regard to the physiological properties of body tissues there are several principles that are worth considering. The first is that running mobilises the catabolic hormones (adrenaline, cortisol) necessary to promote energy metabolism. Catabolic processes break down tissues that must subsequently be prepared by anabolic processes. The art of training is largely about balancing catabolism and anabolism – the most important requirement is ensure that recovery is adequate.

The second valuable principle is that repair of damage tissues involves an inflammatory process that often involves laying down of collagen fibres in a randomly ordered manner. However, the relevant muscle or tendon functions best when the fibres are aligned in the direction of the usual forces, so once the initial inflammation has settled, gentle active recovery helps re-model the tissues in the optimum manner.

Overall, the science of running is complex. Some problems are indeed more challenging than applying quantum mechanics to calculate the energy levels of an electron trapped in an infinitely deep well, but a few simple principles provide most of the guidance a runner needs to maximise the chance of running injury-free.

Reminiscences of 2014: Modifying the marathon training of Ed Whitlock

December 30, 2014

Memories of times past

When I had run marathons in the 1960’s it was an event for wiry young men. Typically a few dozen of us lined up across the roadway at the start. We expected to finish in a time somewhere between 2:15 and 2:45 although we were not fixated on time. In that era the IAAF did not recognise world records for the marathon because courses were not considered comparable. Boston was point-to-point and down hill. Similarly the Polytech Marathon in the UK was a point to point from Windsor to Chiswick.   But despite the fact that the marathon community was a small fraternity of wiry young men who trained fairly hard with little expectation of public recognition, the romance of the marathon was beginning to grow.

At the beginning of the decade, Abebe Bikila had won gold running barefoot in Rome. Four years later in Tokyo, he again won gold in a time more than three minutes faster than his time in Rome. At that time we did not appreciate the significance of Bikila’s Ethiopian origins, but we were inspired by his charisma.

The other charismatic figure of the 1960’s was Arthur Lydiard.   The success of Peter Snell, Murray Halberg and Barry Magee in the Rome Olympics imbued Lydiard’s training method with a magical aura.   Although few of us had read his first book, Run to the Top, that appeared in the early sixties, the key principle of building a base by running 100 miles a week at a good aerobic pace had thoroughly permeated the distance running world via word of mouth. Lydiard had not defined ‘a good aerobic pace’ in precise detail, and most of us probably ran it a little too fast. I usually ran at about 6 minutes/mile which was only about 30 sec /mile slower than my marathon pace. Nonetheless, this pace felt easy. After Percy Cerutty’s daunting Spartan approach with its killer sand-hill runs, Lydiard’s advice ‘to train. not strain’ seemed almost too soft, but the evidence from Rome was proof that it worked.

By 1968, the foundation of the modern marathon had been well laid and the event was about to emerge from the status of a challenging but obscure historic relic reserved for hardy young men. In the preceding December Derek Clayton had run under 2:10 in Fukuoka. Two years later, when I lined up for the start of the Australian marathon championship in Melbourne, I was a little disappointed that Clayton, winner of that event in both 1968 and 1971, was not there.   Not that I would have had any expectation of keeping him in sight for long, but if he had been there it would have nourished the almost-credible but fading illusion of belonging to a small but select fraternity. That same year Frank Lebow and Vince Chiapetta organised the first New York Marathon. Initially it was a small event confined to laps of Central Park, but when the event moved onto the streets of the five boroughs with over 2000 entrants in 1976, the era of the big city marathon had begun.   However, by that stage, I was no longer running marathons. My running had been displaced, initially by mountaineering, and then, after I married, by hill walking.

When I took up running again in my late fifties, the elite event was not all that different. It was a little faster and the Kenyans and Ethiopians were beginning to assert their dominance. The truly amazing transformation had been blossoming of the marathon as a massive community phenomenon. Thousands of runners, tens of thousands in the larger city marathons, started with expectations of finishing times ranging from 2:15 to 6 hours or more.

Out of curiosity I decided to run the Robin Hood Marathon a decade ago.  It was over thirty years since my last marathon, the ill-starred 1972 Polytechnic marathon in which we ran an extra three miles or so, after the lead car broke down and we went off course. More than three decades later, after a brief preparation, I found myself at the start of another marathon, engulfed in a vast ocean of variegated humanity   I spent far too much energy struggling to find some space in the melee, but eventually settled in comfortably     I reached half-way in 93 minutes but not surprisingly, I slowed badly after 20 miles, finishing in 3:27. At that time I considered that it would be a fairly straightforward matter to achieve 3:15 or even perhaps sub-3 hours if I trained systematically.

Little did I realise that I was on the edge of a seemingly inexorable descent into old age.   During my sixties, the various minor health problems that had dogged me for years started to loom larger in my life.   By early this year it was clear that if I wanted again to race a marathon I should not wait too long before embarking on systematic preparation.

Training in spring, 2014

Training this year has been an intriguing adventure. In the spring I began gradually increasing the length of the weekly long run and by early May, I was running up to 34 Km on Sunday morning – very slowly.   I was a little disconcerted by the lingering tiredness and aching connective tissues.  After the long runs I immersed myself waist deep in cold water in a wheelie bin, which provided some relief.  However in June I was knocked sideways by a bout of flu, and then in July, tore my gluteus maximus when leaping full length to catch a ball during a game of rounders – a team building exercise after a long day of project planning with my research team. It was a freak injury with an identifiable immediate cause, but I think that being over-tired makes a significant contribution to most muscle injuries.   Consistent with this interpretation, it took me a while to get going again.

Medical students are encouraged to heed Occam’s Razor: ‘Plurality of causes must never be posited without necessity’. However, in my experience, focusing on a single cause for an event often leads to failure to identify effective future prevention strategies. Summer flu followed by a torn muscle suggested it was time to reconsider my strategy.

Modifying Ed Whitlock’s approach

Rather than exhausting myself in a weekly long run, I decided to try Ed Whitlock’s approach of multiple easy longish runs each week, initially aiming to build gradually to 4 two hour runs per week by mid-December. Ed modestly states that his method works for him, but he is reluctant to recommend it to others. However, even accepting that Ed is endowed with an exceptional natural talent for marathoning and a predisposition to age well, his phenomenal performances suggest that his training can’t be holding him back.   Is there an understandable explanation for the success of his training strategy?

One possibility is that a training load that is spread fairy uniformly across the week is less likely to produce marked transient exhaustion than a traditional marathon program dominated by the weekly long run – even if length of the long run has been increased gradually. Each training session contributes to both fatigue and eventual fitness. In the short term the rise in fatigue is more prominent, but fatigue fades fairly rapidly. The gain in fitness is less immediately apparent, but takes longer to fade away.   At any point during a training program, the ability to resist injury and also the ability to race well, is determined by the difference between accumulated fitness and accumulated fatigue.

Because fatigue fades more rapidly, after an arduous training program, performance is usually enhanced by a taper during which fatigue disappears more rapidly than fitness. Conversely, during arduous training, risk of injury or illness is likely to be minimised by avoiding abrupt increases in fatigue that eat into the margin of reserve between fitness and fatigue.

Following a suggestion from Laurent Therond, I use a fairy simple mathematical model based on plausible values for the rate of decay of fatigue and of fitness to estimate my reserve of fitness during training. (I will post the details of the calculation on my calculation page soon).   The units are arbitrary and the precise numbers should not be taken too seriously, but the principles emerge fairly clearly. In May, following several months of cautious increase in training volume, my fitness reserve typically rose to around 500 units by Saturday, but fell dramatically after Sunday’s long run. For example, after a 34 Km long run in May, my estimated fitness reserve fell from 591 on Saturday to 368 after the long run on Sunday.

More recently, after several months of Whitlock-style training, my fitness reserve remained stable in the range 500 to 600 units throughout the week. Furthermore, my total training load was over 20% greater than it had been in May. However, by the beginning of December, I was just a little disconcerted. My training load was substantially greater than at any time in the past 40 years and I was aware of a mild accumulation of fatigue in some of the long runs. On two occasions I had felt a few fibres in my hamstrings give way when I bounded up a flight of steps to surmount the River Trent flood defences. On each occasion shortening stride alleviated the discomfort, but it indicated that I was not far from my safe limit.

In any case I intended to introduce some progressive runs into my schedule early in the New Year as a part of specific training for spring marathon. I therefore decided in the third week of December that I would cut back to 2 easy two-hour runs per week, and introduce some progressive runs to see how comfortably I could maintain a pace near marathon pace. After a short recovery session on Monday, my reserve fitness score was at an all-time high of 680.   On Tuesday morning, heart rate and heart-rate variability confirmed that I was in a relaxed state, so I set off for a 10K progressive run. After an easy start, I gradually increased the pace and by the end was feeling very fluent. It was a wonderful sensation to be running freely.   Retrospective analysis revealed that my pace in the final stage was 5 min/Km and heart rate at 83% HRR.   In my youth 5 min/Km would have scarcely been a jog, but on Tuesday it was exhilarating. Of course, it is virtually impossible that I could maintain HRR at 83% for a full marathon, so there is no reason to adjust my target marathon time downwards, but the wonderful thing was that I felt more like a runner once again.

On Wednesday I did a short high intensity interval session that I do frequently without overt evidence of exhaustion. I was little disconcerted to find in retrospect that my heart rate was higher than usual. The reason became clear that night. I was kept awake by a rising fever and a horrible cough that sent lancing jabs of pain through my head. The fever lasted for five days, and even since it has settled I have had a rather irritating cough.

A pause for recovery

Our family spent Christmas at my wife’s brother house in the Lake District. My wife’s brother is a former mountain guide and is currently Safety Advisor for a company that provides leadership training in various formats including outdoor adventure. Christmas at his house usually includes an adventure or two. This year it was mountain biking on Christmas Day and caving in the Yorkshire Dales on Boxing Day. It seemed to me that getting a bit of fresh air in my lungs would be more likely to help my recovery than harm it. Though I was the oldest member of the party, I was able to hold my own with the youngsters fairly well on both days. However, when I had to hoist myself onto a rock ledge while my feet dangled freely in the air below, to exit one of the caves, what would normally have been a simple manoeuvre had me struggling to find the required strength and brought home to me that I have not yet fully recovered.

Cycling on Christmas Day

Cycling on Christmas Day

Pause for the group photo. I am fourth from rigth (with dark glasses)

Pause for the group photo. I am fourth from rigth (with dark glasses)

Caving on Boxing Day

Caving on Boxing Day

Exit from Thistle Main

Wriggling out of Runscar Cave



So what is the conclusion? In the final few months of the year, I had achieved a larger volume of training than in any other 12 week period over the past 40 years. At the end of the 12 weeks I was running more fluently than at any time in recent years, though there were a few hints that I was on the edge of over-training. As I began to cut back the volume in mid-December, I was laid low yet again by a viral infection. Occam’s admonition against seeking unnecessary ‘plurality of causes’ would encourage me to look no further than the fact that many of my work colleagues and students had been suffering from upper respiratory infections at the time. The immediate cause of my illness was no doubt exposure to a sea of nasty viral particles. But I suspect that least in my case, training added a little to the vulnerability.

Nonetheless, I consider that on balance, in 2014 I have laid of solid base. Whitlock-style training is a viable proposition. It facilitates the building of a large training volume while avoiding sporadic peaks of stress. But like any training program that pushes the limits of ones reserves, for a cronky old-timer the best laid plans cannot eliminate the element of unpredictability.

The immediate challenge is to throw off the vestiges of my recent upper respiratory tract infection, without losing too much fitness. My experience in recent years is that for an elderly person, fitness dissolves very rapidly during complete rest, so I will aim for an active recovery in which I build up training volume gradually over a few weeks. Once I am back into full training, I will persist with the Whitlock principle of multiple longish runs at an easy pace each week. However if I am to be ready to race a marathon in the spring, I need to sharpen-up a little. Ed relied largely on short races for sharpening, but the demands of my present work schedule make it necessary for me to fit in two of the easy-paced long runs on the week-end, making racing impractical.   On the other hand, progressive runs that reach marathon pace in the later stages provide race-specific experience without sustained stress, and seem to me the form of sharpening that best suits my present circumstances. So my key sessions will include a progressive run along with several longish runs at an easy pace, each week.

Happy New-Year

Running Efficiency

December 2, 2014

Most endurance athletes focus their training on attempting to increase their aerobic capacity (VO2max) and their endurance. Training increases aerobic capacity by increasing the ability to deliver oxygen to muscle fibres and by increasing the capacity of mitochondrial enzymes to generate energy by oxidation of fuel. However our maximum capacity to generate energy by oxidation of fuel appears to be limited by our genes and/or early development.

The traditional approach to improving endurance is the long run. This increases resilience of muscles, tendons and ligaments, and enhances the ability to metabolise fats.   Once we have trained our aerobic capacity to our limit, and we have developed sufficient endurance to sustain us for the duration of our target event, what scope is there for further improvement in performance? The remaining option is increasing efficiency: that is the effectiveness with which we can use energy to produce speed.


Figure 1 shows speed (in metres/min plotted) against rate of energy production (VO2 measured in ml/min/Kg) for three hypothetical athletes. The slope of each line represents the efficiency of each athlete.   The line with medium slope represents the average runner in the sample used by Jack Daniels to derive the VDOT charts in his book ‘Daniels Running Formula’. The steeper line represents an athlete 10% more efficient than average. The less steep line represents an athlete 10% less efficient than average. Greater efficiency indicates a greater speed for a given rate of energy production. Note that the lines are almost straight, indicating that efficiency is nearly constant across a wide range of paces, though there is a minor degree of flattening of each line at higher paces, indicating a somewhat lesser increase in pace for each additional unit of oxygen consumed.

Figure 1: The relationship between pace and aerobic energy production.  These lines are derived from the data used by Jack Daniels to derive his VDOT tables. The middle line (brown) is the data for an athlete who had the average efficiency from the sample studied by Daniels. The upper (blue) line represents an athlete who is 10% more efficient than average.  The lower represents an athlete who is 10% less efficient than average.

Figure 1: The relationship between pace and aerobic energy production. These lines are derived from the data used by Jack Daniels to derive his VDOT tables. The middle line (brown) is the data for an athlete who had the average efficiency from the sample studied by Daniels. The upper (blue) line represents an athlete who is 10% more efficient than average. The lower represents an athlete who is 10% less efficient than average.

If each of the three hypothetical athletes had a VO2mx of 72 ml/min/Kg (typical of an elite distance runner) the athlete with average efficiency would achieve a pace of 350 metres/min at VO2 max while the athlete who was 10% more efficient would achieve a pace of 385 m//min. At 80% of VO2 max (57.5 ml/min/Kg), the athlete with average efficiency would be expected to achieve a pace of 293 m/min while the athlete who was 10% more efficient would achieve 322 m/min. It should be noted that for an athlete with a lower VO2max, the pace at VO2 max and at any given percentage of VO2max will be less, but the relative gain in pace from an increase in efficiency will be similar. In other words, for two athletes with the same VO2max, a 10% improvement in efficiency would result in 10% faster times in races run at any given proportion of VO2max.

Might training produce an increase in efficiency of 10% or more?   The measurements of Paula Radcliffe performed by Andrew Jones for more than a decade provide clear evidence that the answer is yes. In fact, the data shows that Paula achieved a 15% increase in efficiency over the decade from 1993 to 2003*. Her VO2max remained virtually constant at around 70 ml/min/Kg over this period. Thus, a major factor in Paula’s phenomenal marathon record of 2:15:25 recorded in 2003 appears to be the remarkable improvement in efficiency. How might an athlete improve efficiency?  There are two possibilities: increasing biomechanical efficiency and increasing metabolic efficiency.

Biomechanical efficiency

There are three major energy costs of running:

  • overcoming the braking that occurs while on stance;
  • getting airborne;
  • swinging the leg forwards after lift-off from stance.

There is also the cost of unnecessary tension or movements of other body parts, but as is well illustrated by Emil Zatopek and Paula Radcliffe, who both achieved phenomenal performance despite unnecessary upper body movements, the cost of such movements is relatively small, and there is unlikely to be more than a slight gain from reducing them.

Minimizing the sum of the three major costs requires a balance between conflicting effects. At a given cadence (steps/min) braking cost increases as the cost of getting airborne decreases because less time in the air inevitably results in a larger proportion of time on the ground. Although braking only occurs when the point of support is in front of the centre of gravity, braking cost cannot be reduced merely by attempting to land with the foot under the body, because at constant speed the forward-directed impulse generated after mid-stance and the backward directed impulse generated by braking before mid-stance must be equal (after allowing for overcoming wind resistance).  For a give cadence, the cost of braking can only be reduced by spending more time airborne.

During a marathon, many runners spend an increasing proportion of the time on stance as the race progresses. This is likely to result in greater braking and reduced efficiency. It is noteworthy that the well-known picture of Paula Radcliffe at mile 14 on her way to victory in the 2007 New York marathon shows her getting well-airborne. This demonstrates that she had adequately developed reserves of the leg muscle power required to get airborne. Andrew Jones’ measurements demonstrated that her vertical jump performance increased from 29cm in 1996 to 38cm in 2003.

Paula Radcliffe airborne at mile 14 in the New York marathon, 2007.  Photo by Ed Costello, Brooklyn, NY,US

Paula Radcliffe airborne at mile 14 in the New York marathon, 2007. Photo by Ed Costello, Brooklyn, NY,US

The cost of getting airborne can be reduced by increasing cadence, because the body falls a lesser distance during a series so short hops than during a longer hops covering the same distance, simply because a freely falling body accelerates, thereby gaining greater speed the longer it is airborne. The optimum cadence increases with increasing speed, because if cadence does not increase with increasing speed, stride length would necessarily have to increase disproportionately, resulting in heavy costs of getting airborne and also braking. However, there is a limit to the gains that can be achieved by increasing cadence, because the cost of moving the swing leg forwards increases in proportion to cadence (as shown on the my calculations page).

Nonetheless, many recreational athletes have scope for increasing efficiency by increasing cadence. The study by Heiderscheit and colleagues indicates that a typical recreational runner might improve efficiency by decreasing both airborne costs and braking costs by increasing the self-selected cadence by up to 10% . This increase in cadence also reduces stress at the joints by virtue of the reduction in forces required to get airborne and overcome braking.   Heiderscheit reported that a 10% increase in step rate from a self-selected mean step rate of 172.6 ± 8.8 steps/min at a pace of 2.9 ± 0.5 m/s led to an almost 20% reduction in energy absorbed at hip, knee and ankle joints.

It is probable that Paul Radcliffe achieved optimum balance between the cost of getting airborne, braking and advancing the swing leg largely by virtue of fairly intense running, together with hopping drills and weight lifting.   While training near to race pace might optimise neuromuscular coordination, I suspect that the major requirement for optimising mechanical efficiency is adequate muscle power. Although I do not have direct evidence to prove it, I think it is plausible that a small amount of high intensity training will achieve as much gain in mechanical efficiency with less total wear and tear on the body compared with a larger volume of threshold training, simply because training near to maximal effort is more effective for improving muscle strength and power.

Metabolic efficiency

Metabolic efficiency of oxygen consumption is a measure of the amount of mechanical work (and hence speed) that can be achieved from the consumption of a given amount of oxygen. Several factors influence this. The most important is the fact that the efficiency of conversion of metabolic energy to mechanical energy during contraction of a muscle fibre is greatest when the speed of contraction is near the middle of the range of contraction speed that can be achieved by that fibre. When a fibre contracts too slowly it consumes energy developing tension that does little work. Fast twitch fibres have an optimum speed of contraction that several times faster than that of slow twitch fibres. But the speed of fibre shortening during distance running (and also cycling) is better matched to the optimum contraction speed of slow twitch fibres.

It is noteworthy that many of the large muscles that act at hip and knee cross both joints, flexing one while extending the other or vice versa. However during running hip and knee flex simultaneously or extend simultaneously. Consequently, the rate of change in length in these muscle during running is small. Thus type 1 fibres which are well suited to the isometric contractions required to maintain upright posture are also well suited to distance running during which contraction rate is slow.

In the case of cycling, there is direct evidence that efficiency of metabolic to mechanical conversion is greater in individuals who have a higher proportion of type 1 fibres. Although I do not know of any similar measurements in runners, it is very likely that runners with more highly developed type 1 fibres will be more efficient.

The most effective way to develop type 1 fibres is likely to be consistent high-volume training over a sustained period. It is likely that a major part of Paula Radcliffe’s improvement in efficiency was consistent training, with a gradual increase in training volume over a period of a decade. As discussed in my previous post, Paula did a lot of her training at a moderate or high intensity. It remains a matter of speculation as to whether she could have achieved similar phenomenal marathon performances with less damage to her body by a more polarised approach, in which a modest amount of high intensity running was accompanied by a larger proportion of low intensity running. Perhaps she could have achieved similar improvement in metabolic efficiency with a larger proportion of low intensity training over a longer period of time. My own view, based on Skoluda’s evidence that many distance runners have evidence of sustained high levels of the potentially harmful catabolic hormone, cortisol, is that for many athletes a polarised approach offers the best prospect of gradual improvement in metabolic efficiency and hence, the prospect of year-on-year improvement over many years.


Paula Radcliffe’s spectacular 15% increase in efficiency over a period of about a decade, despite an approximately constant VO2max, provides compelling evidence that a worthwhile enhancement of efficiency is possible. It is likely that a combination of high intensity training, hopping drills and weight lifting honed her biomechanical efficiency.  For many recreational athletes, biomechanical efficiency might also be improved by increasing their self-selected cadence by as much as 10%.  It should be noted that optimum cadence increases with speed.

It is also likely that a gradual improvement in metabolic efficiency over a period of more than a decade was also a major contributor to Paula’s improved efficiency.  It is likely that she achieved this by consistent training, with a gradual increase in volume over the years.  Whether or not she might have achieved a similar enhancement of efficiency with a less damaging, more polarised approach to training remains a matter for speculation. Nonetheless, in my opinion, for many athletes, a polarised approach is likely to offer the best prospect of gradual improvement in metabolic efficiency over a period of many years.


*A minor point to note is that Andrew Jones estimated speed at VO2max by assuming a linear increase in pace with increased VO2. This is likely to produce a small over-estimate of actual pace at VO2max, because in reality the curve flattens a little at high values of VO2. Nonetheless, provided all the measurements are made at a similar region of the curve, the error in estimate will be consistent across different measurements. It is pace at around 80% of VO2max that matters most to a distance runner.


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