Am I ‘training smart’?

About 7 weeks ago I formulated a long term plan to prepare for a ‘good’ marathon in three years time – after I have retired from work and when I hope I will have enough time to achieve the training volume necessary for a marathon.

However increased training volume is only part of what is required. In a post on my blog about 6 weeks ago I addressed the perennial question of the relative importance of training volume v. training intensity.  I wrote that when training for endurance events it is necessary to ‘train a lot but train smart’

By training smart, I meant planning a program with identified goals, and being prepared to adjust the program if the goals were not being achieved. I set as the specific goal for the first 12 weeks of my three year program, the recovery of the leg strength that I have lost over the past 40 years – a loss of strength that has left me with a stride length that rarely exceeds 1metre. I also have a background goal of gradual improvement of my aerobic capacity. That background goal will continue to be on the agenda throughout the three year program.

The proposed program

I planned a program for the first 6 weeks that includes the following sessions each week:

1) leg strength – initially focusing on body-weight resistance exercises

2) core strength and upper body strength – also body weight resistance exercises

3) short sprints or stride-outs

4) uphill running (4-6 x 250 metres)

6) a longish run (at least 15Km) in the low aerobic zone

7) two interval or tempo type sessions of 30-45 minutes duration on the elliptical cross -trainer

8. yoga exercise focused on flexibility, balance and body awareness.

I anticipated training for about 4-5 hours per week, and set the target of achieving at least 80% if the specified sessions, to allow for the occasional substation of an alternative activity such a hill walking, swimming, cycling or kayaking.

Planned assessments

To evaluate progress I planned the following tests, to be done in weeks 1 and 6:

1) Hopping test of leg strength: distance covered in 5 consecutive hops on one leg starting from rest. (Best of three attempts with each leg)

2) Sprint speed: the distance covered in 15 seconds.  As I train mainly on woodland or riverside paths, or on soggy grass, I employ my Polar heart rate monitor and S3 foot-pod set to record pace averaged over 3 consecutive 5 second intervals, to avoid the need to measure distance on the ground. However the uncertainty of the measured pace is probably around 3%.

3) Aerobic capacity on the elliptical cross-trainer: average heart rate during a stair case of 7×2minute steps spanning a power output of 30 to 230 watts – anticipated to cover the aerobic zone.

4) Aerobic capacity when running in lower aerobic zone: beats per Km for two segments of 2 km each within the first half of the 15 Km run, selected to cover flat terrain and in opposite directions to minimize the effect of wind.

5) Endurance at low aerobic pace: comparison of beats/Km measured in over a flat 2 km in the final few Km of the 15Km run to assess upward drift of heart rate

I also decided to evaluate upper body strength by assessing the maximum number of consecutive pull-ups – this is probably not relevant to marathon preparation, but is relevant to my overall long term goal of limiting the rate of loss of strength as I grow older.

Progress

I managed to achieve all of the scheduled sessions. After three weeks I felt fairly exhausted. Even though the overall weekly training time was about 4.5 hours per week, all of the sessions apart from the 15Km low aerobic run, the sprints, and the yoga session were quite demanding. Therefore, I reduced the intensity of several of the more demanding sessions a little. For example, during tempo sessions on the elliptical cross trainer, I reduced the target power output from 200 watts to 185 watts. After this slight reduction in intensity, I found I could cope with the schedule without cumulative fatigue

Here is a table of the test results at week 1 and week 6:

 

 

 

 

 

 

 

Test results: week 1 (1 Nov 2009) and week 6 (13 Dec 2009)

 

Leg strength

The most important observation is that the hopping test demonstrates that my leg strength has improved. It should be noted that the weaker performance when hopping on my right leg was anticipated. I have suffered from episodes of inflammatory arthritis since my mid-teens. The right knee has been the most frequent site of the attacks of acute arthritis and after 50 years of these episodes, I now have some evidence of permanent damage. So despite the fact that as a youngster I kicked a football with my right foot and I have always used my right leg for the initial push on the pedals when cycling, I am not surprised that my right leg is weaker than the left. I am pleased that there have been similar increases in strength in both left and right legs, though I am aware of the need to be cautious in the demands I make upon my right leg. However, several studies have shown that exercise is beneficial for joints damaged by arthritis, so I am confident that provided I proceed cautiously, it is reasonable to aim to equalize the strength of my legs.

Upper body strength

The dramatic improvement from 3 to 7 consecutive pull-ups probably reflects the fact that I have done very little to maintain upper body strength in recent years, and even a small amount of resistance work – in fact about 15 minutes per week over the six weeks – has produced a rapid though only partial recovery of my former strength. When I was younger, I could do 10 consecutive pull-ups and I will be very pleased if I can recover that level again.

Speed

I am a little disappointed that there been no discernible increase in my speed – perhaps I need to develop a more reliable test, though the consistency of speed estimates throughout the six weeks suggest that the test at 6 weeks is a realistic reflection of the absence of any appreciable increase in speed. Maybe I need to be patient, and wait until the gains in leg strength are more substantial. Perhaps I also need to do some drills to improve neuromuscular coordination.

Aerobic capacity and endurance

The slight decrease in beats /Km in the first half of the 15 Km run suggests a trivial improvment in my aerobic capacity, but this improvment is not significant.  The lack of substantial change is almost certainly due to the fact that the total volume of aerobic training has been small. If I convert elliptical energy consumption to equivalent distance run using the formula 100 Kcal = 1.6 Km , my average weekly volume of aerobic training in the past 6 weeks has been 34 Km/week. In the 12 weeks prior to starting this program, my weekly average was 41 km/week ( a period during which I was recovering from illness in mid-summer). The average over the preceding 10 months since January 2009 was 45 Km per week. The inclusion of resistance training has necessarily resulted in a reduction in aerobic training volume, so perhaps it is not surprising that my aerobic capacity has not improved.

The only reason for anticipating any improvement despite the reduction in volume was the fact that during the preceding few months I had been recovering from an episode of illness. However, despite the lack of improvement in the past six weeks, it is pleasing to see that even at the beginning of the current six week program, there was no upwards drift of heart rate during a 15Km run in the lower aerobic zone. Hadd suggests that it is time to increase the pace of aerobic training when heart rate remains stable during a 10 mile run (16Km), so perhaps it is time to increase the pace of my lower aerobic runs.

The next 6 weeks

In the remaining 6 weeks of this 12 week cycle, the main goal will be to continue to increase my leg strength. The current program of body-weight resistance training appears to be beneficial, so I will increase the amount of this work from 30 min per week to 45 min per week. I will also introduce some low intensity plyometrics (hopping; lunge jumps etc). Eventually I will increase the resistance in the resistance sessions, by using dumbbells or barbells, but I am in no hurry to do this in light of the need to be cautious in loading my right knee.

I will experiment with some drills to improve neuromuscular coordination with the goal of improving my sprint speed, but increased sprinting speed is not high on my list of priorities and therefore I cannot afford to devote a great deal of time to these drills in the near future.

Because my total training time is limited there is no scope for increasing aerobic training volume at present. I will increase the speed of the 15 Km runs a little, but I am also aware of the need to avoid making all my sessions intense. At present I am enjoying the easy 15Km run each week, and I do not want to make this session onerous. I am confident that if I am patient, my aerobic capacity will eventually begin to increase. I am aiming for 600 beats/Km when running in the low aerobic zone, by the end of next summer.

Paula Radcliffe and Running Efficiency

In recent weeks, I have been focusing on developing a program which will allow me to run a good marathon in 2012. Although I would not wish to rely too heavily on the training of elite athletes to guide me, I have nonetheless been quite strongly influenced by the training program that turned Paul Radcliffe from a promising junior distance runner who won the World Junior Cross Country championship in 1992 into one of the most amazing marathon runners the world has ever seen.

VO2max or efficiency?

According to Andrew Jones, the physiologist who has supervised the measurement of Paula’s aerobic capacity and running efficiency over a period of more than 15 years, the major factor in her improvement was a 15 percent increase in her running efficiency between 1991, a year before she won the World Junior Cross Country championship, and 2003 when she set a world woman’s marathon record of 2hr 15 min 25 sec in London. (International Journal of Sports Science & Coaching Vo1 • pp101-116 • 2006).

If we ignore the minor ups and downs in the measurements, her maximum aerobic capacity (VO2max ) remained approximately constant at 70 ml/min/Kg from age 17 in 1991, to age 29 in 2003. However her oxygen consumption at a pace of 16 Km/hr (6 min/mile) decreased from 205 ml/Kg/Km in 1992 to 175 ml/Kg/Km in 2003, which represents a 15% increase in efficiency (i.e. 15% reduction in the amount of oxygen consumption per Km at a standard pace).

 Andrew Jones acknowledges that he does not know which physiological variable has made the greatest contribution to this improvement in efficiency. Among the various measurements he performed were blood lactate at various paces; heart rate at various paces; vertical jump height and the sit-and-reach test of lower body flexibility. All of these measurements changed significantly over the relevant time period.

The lactate turn point

Most striking was the right shift of the turn-point in the graph of blood lactate against pace. In 1992, there was an appreciable upturn of lactate (from 1.2 to 1.45 mM/litre) between 13 and 14 Km/hour. By 2003, her blood lactate level remained almost constant in the range 1.2 – 1.4 mM/litre up to 18.5 Km/hr and then turned upwards sharply.

At first sight, this might indicate a substantial increase in ability to deliver oxygen to the tissues (perhaps via increased diameter or density of capillaries) and/ or increase in number of mitochondria in muscle fibres so that fuel is burned aerobically rather than anaerobically. However, one might expect that if such changes were generalized to all aerobic muscle fibres, these changes would also produce an increase in VO2 max. In view of the fact that VO2 max did not increase substantially, it suggests that the changes are predominantly changes in blood supply and mitochondria in slow twitch fibres.

Andrew Jones reports that during the relevant years she increased her ability to cope with a relatively large training volume, so that by 2003 she was running up to 160 miles per week. Jones reports that a large proportion of Paula’s training was steady paced running typically running at a pace of 3:30 to 3:40 min/Km. For most people, these paces would be well above the lactate turn point, though by 2003, at 3:20 min/km Paula’s blood lactate level was only about 1.4mM/litre. A large volume of training at this pace would be expected to develop the capillaries and mitochondria of slow twitch fibres. It is noteworthy that 3:20 min/Km corresponds to a marathon time of 2 hrs 20 min and thus is not far below her race pace. Thus I am inclined to speculate that it is likely that the most significant development that allowed her to run a marathon in 2:15:25 was the development of capillaries and mitochondria of slow twitch fibres.

However, it should also be noted that even at paces corresponding to VO2max, her blood lactate level was only around 5mM/litre, which is around half the expected value for a typical athlete. This suggests that she also had a highly developed capacity to metabolize lactate. This would have made her use of fuel at marathon pace more efficient.

Muscle power

In addition, other factors almost certainly contributed. As an old timer with noticeably reduced muscle power, my attention was caught by the observation that her vertical jump performance increased from 29cm in 1996 to 38cm in 2003. Perhaps the most important contribution to developing her muscle power arose from the efforts of physiotherapist Gerard Hartmann to identify the problem that had left Paula struggling in the wake of three faster runners in the final lap of the 10,000m in the Sydney Olympics in 2000.

In an article published in Running Times in 2004, athletics journalist, Frank Greally, reported an interview with Hartmann, in which Hartmann described how, after the 2000 Olympics, he had asked Paula to do 20 hops up and down from a 16 inch high box as fast as she could. Whereas Kelly Holmes had achieved 20 hops on and off the same box in 12.5 seconds, Paula took 27 seconds on her first attempt. This led Hartmann to devise a program of plyometric exercises and heavy weight sessions. In 2002, Paula won her first senior world title (long cross country in Ostend, Belgum) and also her debut marathon in London, where she achieved the second fastest time ever for woman (eight seconds slower than Catherine Ndereba’s record of 2:18:47).

Head nodding

Another problem that Hartmann had addressed following the disappointing 4th place in the 10000m in the Sydney Olympics was Paula’s characteristic head-nodding style. Hartmann demonstrated that this arose from weak neck and shoulder muscles and devised a program of strengthening exercises which has largely cured her head nodding.

Is flexibility good?

An intriguing but probably a less important factor was the deterioration in Paula’s lower body flexibility over the period from 1991 to 2003. Andrew Jones reports that in 1991, in the sit-and-reach test she reached 8cm beyond her toes in 1996, but only 4cm beyond her toes in 2003. This observation demonstrates that a high degree of flexibility is not essential for world class performance, and raises the possibility that too much flexibility might actually be associated with diminished efficiency.

Conclusion

In conclusion, the evidence suggests two major developments contributed to Paula’s increased efficiency and dramatically improved performances. The first was a strong rightward shift of the lactate turn point, possibly due largely to development of capillaries and mitochondria in slow twitch fibres and to increased ability to metabolize lactate. Secondly, a program of plyometrics and weight training led to a major increase in her leg muscle power, reflected in vertical jump capacity, and in her neck and shoulder muscles, alleviating her previous inefficient head nodding style. It is likely that the increased power of her leg muscles allowed her to spend a shorter time on stance and to lengthen her stride, in the manner described by Weyand in the study which I described in my blog post on 22nd November.

 2003 – 2012

Since 2003, Paula has continued to record great achievements in the marathon, with three victories in New York (2004, 2007 and 2008); first place in London in 2005; and a gold medal at the world championships in Helsinki in 2005. Sadly, an Olympic medal still eludes her. She now has her sights on the London Olympics 2012. By then she will be 38. I understand that Catherine Ndereba, who had preceded Paula as the woman’s marathon world record holder in 2002; won gold at the world championships in 2003 and 2007; and silver at the Olympics in Athens in 2004 and Beijing in 2008, is also planning to race in London. Catherine will be 40 in 2012. It would be wonderful if both are in great form for that race. It would be hard for anyone with a sense of sportsmanship to begrudge Paula a medal.

Whether or not Paula is able to produce medal winning form in 2012, her story illustrates that a systematic approach to training, focusing on aerobic development, leg strength and running technique has turned a promising junior into one of the most wonderful athletes ever.

Weyand v. Pose: it’s the push that counts

A few weeks ago, I presented an overview of my plan to get fit enough to run a ‘good’ marathon again in 3 years time. Each 3-4 month period will have a specific goal in addition to the continuing basic objective of improving my aerobic capacity. The specific goal for the first 4 month period is recovering some of my lost muscle strength, largely by resistance exercises and drills, together with a small amount of sprinting and uphill running.

Although I have now completed the first three weeks of the program, I have not fully settled the question of what leg strength exercises and drills are likely to be most beneficial. At present the exercises that I am doing are mainly body-weight exercises performed standing on one leg (such as one leg squats , hip swings, calf raises etc) since the major muscle actions of running are executed while standing on one leg. I am also doing a very small amount of plyometric exercise to increase my capacity to deal with eccentric contractions but in view of the risk of long term damage, I am being quite sparing with these exercises. I plan to test for gains in leg muscle strength (assessed by a hopping test, and by measuring my sprinting speed) after 6 weeks and if there has not evidence of substantial gain, I will modify the types of exercises and drills in my program.

In preparation for this, I have been once again reviewing the question of running technique in order to identify what exercises and drills are likely to be most beneficial. Two apparently coincidental happenings in the past two weeks have also served to re-focus my attention on running style.

 Gravitational torque

One has been a series of comments by Simbil on a post entitled ‘if gravitational torque is a red herring, how to do we run fast?, which I had posted in February. Simbil is a runner and thinker based in Sheffield, who contributes thought-provoking comments to the Efficient Running thread on the Fetch website. He is an advocate for Pose technique, though he is prepared to re-examine the tenets of Pose in a thoughtful manner. Gravitational torque plays a crucial role in the theory of Pose. Simbil has been challenging my assertion that the gravitational torque that generates head-forwards and downwards angular momentum in the second half of the stance phase is balanced by an oppositely directed torque acting in the first half of stance. We have been lobbing arguments back and forth for some time. We have not yet reached any definitive conclusion, though we are in agreement that the gravitational torque must be counteracted by an oppositely directed torque acting a some point in the gait cycle, and furthermore, that whatever the mechanism, the forces involved in generating gravitational torque and compensating for it are far less important that the forces required to get airborne. I will return to this issue a little later.

Pose Tech

The other coincidental happening came to my attention when I noted a little upwards blip in the number of hits on this site a little over a week ago. At present this site gets about 2000 hits per month (far below the league of the Huffington Post or Belle de Jour, or, I suspect, Younger Legs for Older Runners, but nonetheless, satisfying). Most of the hits come from Google searches seeking information about various aspects of running technique and training, though the flurry of increased activity in the few days after each posting indicates that there are also some faithful followers. It always gives me a little thrill to see these flurries of activity and I hope that those of you who read the posts find them interesting. In addition there are occasional flurries of increased activity at other times indicating that some other website has drawn attention to something on my site. One such flurry occurred last week, and inspection of the stats provided by WordPress revealed that the hits were referred from one of the forums on the Pose Tech website. Those forums are protected by password, but as runner interested in Pose, I have been registered with the site for several years. So I was tempted to have a look.

When I logged on I was intrigued to find that there was a quite active thread discussing my blog. Those of you familiar with the Pose Tech site will probably be aware that many of the people who post on the forums are strong believers in Pose. Therefore, I was more amused than surprised to see comments such as ‘burn the heretic’. However a gratifyingly number of the postings were in agreement with my views, especially my view that landing on the ball of the foot, in combination with a short time on stance places large forces on the foot, and is associated with risk of injury to metatarsals and connective tissues of the foot and ankle.

I was a little saddened by a passionate posting from Lana, the wife of Nicholas Romanov [correction: Lana is his daughter, see comments below], lamenting the fact that I and others did not give due credit to the amount of work and expertise that her husband has devoted to the Pose technique. However, while I am happy to acknowledge the work and expertise of Dr Romanov, I think there is a serious issue arising from the fact that the 2002 edition of Pose Method of Running reproduces the diagrams and photos from the first edition showing the heel held high off the ground at mid stance. In the early years, it was quite common for Pose novices to report Achilles or calf muscle problems, which I think are largely due to holding the heel off the ground. The importance of these problems was reinforced by the findings of the Capetown study (Arendse et al, Medicine & Science in Sports & Exercise: Vol 36 pp 272-277, 2004) demonstrating that Pose is associated with increased stress around the ankle, together with the reports by Ross Tucker (who assisted Dr Romanov in coaching the Pose technique in that study) that the runners in the Pose group suffered a high rate of injuries to connective tissue around the ankle (http://www.sportsscientists.com/2007/09/running-technique-part-ii-scientific.html).

When I expressed disappointment that these figures had been reproduced without anything in either text or illustrations (as far as I have been able to ascertain) describing how the risk of these injuries might be minimized by relaxing the ankle to allow the heel to touch the ground, Lana suggested that ‘you need to “zoom out” a bit – because you are not doing yourself any favours by using a magnifying glass all the time’. In an email, a good friend has suggested that it is unlikely that I will be on Lana’s Christmas card list this year.

Despite this little storm in a tea-cup on Pose Tech, I have a fairly positive view of how Pose works in practice, based not only on looking at the evidence through a magnifying glass; but also by talking to runners who have applied it; and by experimenting with it myself. I am less impressed with the theory underlying Pose, but the evidence that the technique can be beneficial makes me want to understand more clearly why it works

A subjective overview of Pose

Many of the principles of Pose such as high cadence, short time of stance; avoiding reaching out with the leading foot, and keeping the pelvis forward, make mechanical sense. I discuss these features in my own account of technique (‘Running: a dance with the devil’ – listed on the side panel). Many elite athletes exhibit these features despite never having been trained in Pose, though I think Nicholas Romanov deserves credit for publicizing these principles among amateur runners.

Other features such as landing on the ball of the foot (BOF) also make sense, but are attended by risk. As I had mentioned in my comments on Pose Tech that provoked the anguished response from Lana, BOF landing places substantial stress on the bones and connective tissue of the foot and lower leg, and creates a risk of repetitive strain injury to metatarsal, planate fascia, Achilles tendon and peroneal tendons. At least when running long distances, I consider it is best to relax the ankle so that the heel brushes the ground in mid-stance

I also consider that Dr Romanov’s claim that gravitational torque provides the motive force for running is misleading. According to the law of conservation of energy, it is impossible for gravity to provide net energy when running on a level surface. I accept that the unbalancing due to gravitational torque during the second half of stance does help promote the muscular actions necessary to swing the leg forwards in time to support the body at subsequent footfall. However I am not convinced that this is plays a major role, and I therefore consider that gravitational torque is probably a red herring. Nonetheless, I am quite happy to continue debating this issue with Simbil.

However in my opinion the most interesting issue for debate is the concept of pulling from stance rather than pushing. The Pose mantra is ‘Pose, Fall, Pull’ implying that the crucial actions are:

1) adopting the classic pose with the point of support (BOF), hips, and shoulders aligned, in mid-stance;

2) falling under the influence of gravitational torque as the centre of mass moves in front of the point of support;

3) pulling the leg from stance by means of a contraction of the hamstrings.

In practice, I think that getting airborne is impossible without a push. Pulling from stance would amount to lifting oneself by one’s own boot straps. Of course pulling the leg forwards by hip flexor contraction once airborne is essential, but is largely automatic. While I think that pulling from stance is largely an illusion, I think it might be a useful illusion to cultivate because it encourages a short time of stance, high cadence and relatively short strides – possibly not the best style for record breaking performances, but nonetheless fairly safe. For most of us, avoiding injury is more important than maximizing mechanical efficiency.

So, while I think that the Pose concept of pull is not mechanically correct, I think that it is a useful mental image to cultivate, in the same way that some of the principles of Alexander technique are based on creating helpful illusions. Therefore, Pose drills such as Change of Stance that encourage the illusion of pulling are probably useful. But if one want to increase one’s speed of running, are Pose drills more important that developing the muscles responsible for the push?

Weyand: it’s the push that counts

Perhaps the most important evidence about the muscular action required for running fast comes from a study by Peter Weyand and colleagues from Harvard (J Appl Physiol Vol 89: pp 1991–1999, 2000). In a study of runners with various different maximum running speeds, using a force plate to assess ground reaction forces during treadmill running, they demonstrated that ‘human runners reach faster top speeds not by repositioning their limbs more rapidly in the air, but by applying greater support forces to the ground.’ The force plate data showed clearly that a larger vertical ground reaction force achieved by the foot pushing against the ground was the main factor distinguishing fast runners from slower runners.

The extensor paradox

However, Weyand’s findings present a problem: the extensor paradox. Studies employing electromyography to measure the electrical activity in muscles demonstrate the major muscle groups that would be expected to execute a push off the ground, especially the quadriceps which are responsible for knee extension, are almost silent in late stance (Elliot et al. Medicine & Science in Sports vol 11, pp 322-327, 1979). So where does the push come from? Much of it almost certainly comes from elastic recoil of quadriceps, acting in conjunction with the hamstrings, and soleus, all of which have been stretched on impact at foot fall. Thus the crucial strength that is required for running fast is the ability to sustain a strong eccentric contraction of the quads, hams and calf muscles.

Conclusions

In a program to rebuild the strength necessary to run fast, it is crucial to recover the capacity for strong eccentric contraction of quads, hams and calf muscles. Of course other muscles also play a role – especially the gluteals which help hold the pelvis in a horizontal position during swing, and the hip flexors, which drive the swinging leg forwards – but Weyand’s study indicates that it is the ability to push strongly that distinguishes fast runners from slow runners. Clearly any strengthening program should involve a reasonable balance between all relevant muscle groups as muscles do not work in isolation, but nonetheless, much of the focus should be on eccentric strengthening of quads, hams and calf muscles.

However there is a problem: as I have discussed several times previously on this blog, eccentric contraction damages muscle, possibly permanently, especially in older runners. So a program of plyometrics designed to increase the ability to withstand eccentric contraction must be undertaken cautiously. I am inclined to think that the first priority is to recover strength of the major muscle groups, especially quads and hams with a program of resistance training with free weights, including a gradual build up of eccentric loading, before moving on to a modest amount of plyometrics. Meanwhile, I will also continue with regular uphill running, as this invokes the required muscular actions in a way that is ‘natural’ for a runner.

As for drills, any drill that promotes a short time on stance is likely to be beneficial. I am still exploring the options, but despite my opinion that the pull is less important than the push in getting airborne, I think that the Pose ‘Change of Stance’ drill is beneficial, even if it is largely cultivating a beneficial illusion of pulling from stance.

Train a lot but train smart

In proposing the toast at a dinner celebrating Espen Tǿnnessen’s successful defence of his PhD thesis, in Oslo in June 2009, Dag Kaas, coach of world champion cross-country skiers and orienteers remarked, ”My experience as a coach tells me that to become world champion in endurance disciplines, you have to train SMART, AND you have to train a LOT. One without the other is insufficient.”

This anecdote is recounted in an excellent review by Stephen Seiler and Espen Tǿnnessen entitled ‘ Intervals, Thresholds, and Long Slow Distance: the Role of Intensity and Duration in Endurance Training’ published this month in Sportscience (Vol 13, 32-53, 2009). Simon Wegeriff had provided a link to this in his comment on my post on 8th November describing the study by Esteve-Lanao. Esteve-Lanoa and colleagues provided a fairly convincing demonstration that a polarized training program in which about 80% of the work is done at low intensity, is more effective that a program including a higher proportion of work in the mid-zone, near to lactate threshold.

In their review, Seiler and Tǿnnessen present a contrast between the mixed bag of evidence from scientific studies of benefits of high intensity v low intensity training, with the observations from the training of selected elite endurance athletes. To obtain a full appreciation of the evidence it is best to read the full review. Here I will focus on a few issues that caught my attention.

Who are the authors?

Perhaps the first issue when reading a selective review article is appreciating the background of the authors. There is no reason to doubt that Seiler and Tǿnnessen are rigorous scientists with a commitment to establishing the truth. However, a scientist’s background inevitably influences the way in which evidence is selected and evaluated. The senior author, Stephen Seiler, is a strong advocate for polarized training: a large amount of low intensity training, together with a small amount of high intensity training, and a minimal amount on the intervening grey zone. He was one of the co-authors of the report on the Esteve-Lanao study, and had also previously led a study of autonomic recovery following low, medium and high intensity sessions, in which the low intensity sessions were associated with the most rapid recovery. Espen Tǿnnessen’s doctoral dissertation included detailed analyses of the training of selected world champion female endurance athletes. He examined training diary logs of over 15,000 training sessions from three World and/or Olympic champions: Bente Skari (cross-country skier), Hanne Staff (orienteer) and Ingrid Kristiansen (marathon runner). The feature common to the selected champions from the three disciplines was that about 85 % of their training sessions were performed as continuous efforts at low to moderate intensity (with blood lactate less than 2 mM).

Thus, Seiler and Tǿnnessen had good reason to approach this review with a bias towards polarized training. The bias shows through in the use of phrases such as ‘In view of the recent hype and the explosion in the number of studies investigating interval training…’ While their selection of data includes studies favoring high intensity training in addition to studies favoring low intensity training, to my eye, there is a degree of bias in the selection.

Evidence regarding African training

For example, in discussing the training programs of Africans they start with the challenging statement: ‘Kenyan runners are often mythologized for the high intensity of their training’ and go on to refer to their own re-analysis of the data collected by Veronque Billat which led them to conclude that elite Kenyan 5- and 10-km runners ran ~85 % of their weekly training kilometers below lactate-threshold speed. However, they make no mention of the study in which Tim Noakes and colleagues compared elite black African runners with elite white Africans and found that the black runners did 36% of their running at above 80% of VO2max, while the white runners did only 14% of their running above this level (Journal of Applied Physiology, vol. 75, pp.1822-1827, 1993).

Training logs of elite athletes

Seiler and Tǿnnessen present compelling evidence for major improvements in both performance and in physiological variables such as VO2max, after a change to a training program with a higher proportion of low intensity training, in the case of two Norwegian athletes: Øystein Sylta, and Knut Anders Fostervold. Sylta was a military pentathlete, who was European champion in 2003, and subsequently became an elite distance runner. Fostervold was a professional soccer player who switched to cycling after a knee injury ended his football career at age 30. He subsequently represented Norway in the world championship time trials in 2006 and 2007.

However, they make no mention of Norway’s greatest female marathon runner, Grete Waitz , who won the New York marathon 9 times, a silver medal in the 1984 Olympics in LosAngeles, and gold at the 1983 World Championships. As far as I have been able to determine, Waitz did a lot of training at mid and high intensity. For example, in an article by elite Norwegian distance runner Marius Bakken, based on Waitz’ training diary; and on talks between magazine writer, Lief Tjelta and Waitz herself; and also on talks between Bakken and one of Waitz’ mentors, Johan Kagestad, Bakken claims: ‘The most mileage for one week came in 1976 with 180 km/week. Her mileage at this time was never long and slow. She often ran it with the boys at a steady 3.30-3.45/km pace, which is quick for a female athlete (according to Kagestad). This indicates a sub AT type training to build endurance.’ http://www.mariusbakken.com/index.php?parent=11&groupid=22   Marius Bakken has a reputation for racing with tiger-like ferocity and tends to advocate a substantial amount of moderate and high intensity training. It might be possible to offer alternative interpretations of Grete Waitz’ training diary. The point I wish to make is that in the much debated question of the merits of high intensity v low intensity (high volume) training, one needs to take account of possible biases in the way in which the data is selected and presented. Notwithstanding this important caveat, I think Seiler and Tǿnnessen present a large amount of very valuable information in their review.

Differing physiological benefits at different intensities

Among the things that struck me was their discussion of the possible differences in the physiological benefits of high intensity and of low intensity, high volume training. They conclude that both forms of training are likely to lead to increased activation of fast twitch muscle fibres producing a beneficial increase in metabolic activity in these fast fibres. High intensity training will recruit these fibres early. In the case of low intensity, high volume training they propose that the fast fibres will be recruited after exhaustion of slow fibres. It might be expected that this benefit would greatest after long runs –suggesting that one long run might be better for this purpose than two shorter runs. They also indicate that high intensity training will produce increased filling of the heart and increased end-diastolic volume, thereby producing a beneficial increase in maximum stroke volume and maximum cardiac output. In addition they propose that high intensity training might lead to increased vascular supply to muscle fibres as a result of local mechanical and metabolic signals. In addtion, they  list several other possible physiological benefits of each type of training. The overall conclusion appears to be that high intensity training is likely to be more efficient for certain types of beneficial physiological development, especially in the cardiovascular system, but low intensity training also has its advantages. Thus, ‘smart’ training should include an appropriate proportion of high intensity training in addition to low intensity training. It is crucial to note that Seiler and Tǿnnessen do not argue against the inclusion of high intensity training; they are mainly arguing for polarized training with a relatively small proportion of high intensity training and avoidance of the ‘grey’ mid-zone. They argue that tiredness from mid-zone training impedes the ability to perform the high intensity sessions well.

Differences between individuals

Another important point raised by Seiler and Tǿnnessen is that individuals differ. They describe a 2 year study of cross-country skiers by Gaskill and colleagues, in which all the athletes trained similarly with about 16% of training at lactate threshold or higher, in the first year. By the end of the first year, half of the athletes had shown substantial improvement in race performance and in physiological measurements. In the second year, those who had shown improvement continued on their established training program, while those who had not improved in the first year, undertook a program with more high intensity training. In the second year, the previously poor responders improved significantly on the higher intensity program, while the previously good responders continued to improve on the established program with only 16% at or above lactate threshold. I think the lesson is that whatever program one adopts, one must monitor progress and change if the expected improvement is not occurring.

Training smart

Overall, I consider that Seiler and Tǿnnessen present a strong case for polarized training with a high proportion of low intensity sessions. However, I also think that Dag Kaas is right: it is necessary to be smart in addition to training a lot. Each individual needs to work out a program that addresses his or her specific needs; invest faith in that program for an adequate length of time while monitoring progress, and if progress is not occurring, make appropriate adjustment. In my next two posts I intend to deal with what adjustments in a training program are required to deal with some of the limitations of the older runner, and I will also describe the testing procedures that I am incorporating in my own program.

The grey zone

In recent posts I have discussed the evidence regarding the relative merits of high intensity training and high volume training.  The evidence demonstrates that both approaches are effective for increasing aerobic capacity.  Both will develop capillaries and mitochondria in heart and skeletal muscles.  High intensity training allows a more efficient use of time, which might be the decisive feature for an amateur athlete with family and work commitments, though in general, high intensity work-outs are tougher and require greater determination. 

Potential benefits of mixing high and low intensity

Furthermore the two approaches are each attended by risk of injury or over-training.  However it is probable that the risk of injury and over-training associated with the two intensities of training arise from somewhat different stresses on the body.  High intensity training produces greater forces on the musculo-skeletal system, but also produces greater increases in anabolic hormones, whereas high volume training produces greater increases in catabolic steroids such as cortisol, which can promote destruction of muscle if excessive.  On the other hand, there is relatively little evidence suggesting that a high intensity session undoes the benefits of a preceding low intensity session or vice versa.  Therefore, my provisional conclusion is that the best approach is a program that includes a mixture of high intensity and low intensity (high volume) sessions, on the grounds that such an approach is likely to achieve a good balance between stimulation of catabolic and anabolic hormones. This remains unproven but is at least plausible.

What about the mid-zone?

However, this leaves unanswered the question of whether or not training sessions that fall in the mid-zone between high intensity and low intensity (but high volume) are of much value.  Surveys have shown that elite athletes tend to avoid the ‘grey’ zone between high intensity and low intensity,  For example, the study by Seiler and Kieland found that elite skiers do about 75% of their training at low intensity and 15-20% at high intensity with only around 5-10% in the mid intensity range  (Scand J Med Sci Sports. 16(1):49-56, 2006).  Previously the French exercise physiologist, Veronique Billat, had reported similar proportions of time in the different training zones in marathon runners (Med. Sci. Sports Exerc. 33:2089–2097. 2001)

The Esteve-Lanao study

It was therefore with great interest that I read a report on a study by Jonathan Esteve-Lanao and colleagues (Journal of Strength and Conditioning Research, 21(3), 943–949, 2007), which had been pointed out to me by Simon in a comment on my post comparing high and low intensity training on October 25^th.   Esteve-Lanoa is a coach in Madrid who had previously published findings demonstrating that the proportion of training time spent in the low intensity zone was a strong predictor of race performance (Med Sci Sports Exerc. 37(3):496-504, 2005.) 

In the more recent study published in 2007, he allocated a group of well-trained sub-elite athletes to one of two programs for a period of 5 months: one program included more low intensity training than usual for this group of athletes; the other involved less low intensity training and more mid-intensity training.  Both groups performed the same amount of high intensity training.  Intensity was assessed according to proportion of training time with heart rate within low, mid and high intensity zones defined relative to the ventilatory threshold (VT) and respiratory compensation threshold (RCT). 

Defining the zones:  VT is the first appreciable step in respiratory effort as work load increases, and corresponds to the threshold described as VT1 by some authors (eg Dekerle and colleagues) or aerobic threshold by others.  It is the highest work rate that can be fueled virtually entirely via aerobic metabolism. At higher work rates, appreciable anaerobic metabolism occurs, and lactate level rise appreciably above resting values.  The increased acidity in the blood causes the noticeable rise in respiratory effort necessary to remove more carbon dioxide, thereby compensating for the lactic acid by reducing the acidity due to dissolved carbon dioxide.   Lactate is removed by organs such as liver and heart which can use lactate to generate energy.   As work rate rises further, a stage is reached beyond which the body cannot remove the lactate as fast as it is produced.  At this stage lactate level and acidity rises rapidly.  There is a major drive to increase respiratory effort in an attempt to compensate for the acidity.  This is the respiratory compensation threshold (RCT), which is also known as VT2 or anaerobic threshold.   Thus, in the study by Esteve-Lanao, low intensity training at a heart rate below that corresponding to VT is virtually entirely aerobic.  In the mid-intensity zone between VT and RCT, training involves some anaerobic metabolism but the body can cope with the rate of lactate production and lactate level remains only a little above resting value.  In the high intensity zone above RCT, a large proportion of the energy is generated by anaerobic metabolism and the level of lactate rises to high levels, compelling the athlete to make a very strong respiratory effort in an attempt to deal with the rising acidity. 

The results:  In the group assigned to an increased amount of low intensity training, the amounts of times in heart rate zones corresponding to low, mid and high intensity training were in the ratio 80:12:8 (i.e. 80% low intensity).  For the group assigned to decreased low zone training, the ratio was 67:25:8  (i.e. 13% less in the low zone, replaced by 13% more in the mid-zone).  In both groups VT occurred at approximately 67-68% of VO2max, while RCT occurred at approximately 87-88% of VO2max.  The outcome of training was assessed by comparing time recorded in a 10.4Km cross country race before and after the 5 month period of training.  The group who had HR in the low zone for 80% of the time improved by 7.5% while the group who had HR in the low zone for only 67% of training time, improved by 5%.  The difference between groups in amount of improvement was statistically significant.  It should be noted that the individuals with HR in the low zone for 80% of the time spent more hours training (average 100 hours over 18 weeks compared with average 75 hours in the group with HR in the low zone for 67% of the time), but the total load (volume x intensity) was similar in the two groups. The authors conclude: ‘These results provide experimental evidence supporting the value of a relatively large percentage of low-intensity training over a long period, provided that the contribution of high-intensity training remains sufficient.’

It is crucial to note that even the group with 80% low intensity training performed a substantial amount of demanding work. They did 2 intense sessions per week in many of the weeks, in addition to regular weight training, and also running 5 cross country races (2 x 5Km and 3 x 10Km) not including the final assessment. Nonetheless, I think the practical conclusion is that training in the mid-zone produces less benefit that a similar work load (volume x intensity) in the low zone provided the program includes sufficient high intensity work.

It should also be noted that the amount of time spent with heart rate corresponding to the mid-zone intensity does not correspond exactly to the amount of time spent working in this zone.  Typically in an interval session, it takes from 1 to 2 minutes for HR to reach the high intensity zone (due to buffering by myoglobin) during high intensity epochs, and it takes 1 to 2 minutes before HR falls back to low zone level during the recovery.  When I do 1 Km intervals, my heart rate is in the mid-zone for more than half of the session despite the fact that I do not spend any time running at a mid-zone pace.   To achieve 8% of training time in the high intensity zone typically would require about 15% of sessions to be high intensity sessions.   

On the whole this appears to be a sensibly designed and well executed study.  The main concern I would raise is the fact that Esteve-Lanao’s previous study published in 2005, in which he found that the amount of low intensity training predicted race performance, might have inclined him to have greater faith in low intensity training.  He coached all the athletes in the study reported in 2007.  There is evidence that having faith in a particular training program influences the physiological benefits from that program.  It is therefore possible that coach’s confidence in the low intensity program influenced the outcome.   It is because of unconscious influences of this sort that double-blindness is regarded as so important in trials of medical treatments.  Nonetheless, despite this potential short-coming, I consider that this study provides moderately strong support for the proposal that mid-aerobic ‘grey zone training’ is a limited value.

The beginning of a 3 year program

As described in my post on 25^th October, the events of the past summer indicate that I need to plan a long term campaign if I am ever to recover a level of fitness equivalent to that of my younger days, after allowing for the anticipated rate of decline with age illustrated by the WAVA charts.   My goal is to run a ‘good’ marathon in 2012, perhaps aiming for a target time in the range 3:15 to 3:30, and to continue to enjoy running for many years after.

What needs to be developed, and how can the required development be achieved? 

1)    Aerobic capacity of leg muscles: the ability to generate energy for muscle contraction by aerobic metabolism is crucial. The aspects of aerobic metabolism that can be improved by training are:

a.  Delivery of oxygen to the muscles – the number and size of capillaries increases when there is demand for increased delivery of oxygen to muscles;  development is likely to continue over many years provided the there is continuing demand for increased oxygen delivery.   Both low intensity and high intensity training are effective.  The study by Ingjer (J. Physiol. Vol  294, pp. 419-432, 1979) reported an increase of 28.8% in the number of capillaries per muscle fibre after 24 weeks of a high intensity program that included two interval sessions per week in addition to 3 sessions of continuous running for 45 minutes at a work rate ranging from 50 to 90% of VO2max.

 b. The number of mitochondria in type 1 (slow twitch) and type 2A (aerobic fast twitch) fibres. The mitochondria are the sub-cellular organelles containing cytochrome oxidase, the key enzyme in aerobic metabolism.  Dudley’s studies of rats (J Appl. Physiology, vol. 53, pp. 844-850, 1982), discussed in my post on 25^th October, demonstrate that increase in cytochrome C is achieved most efficiently for both type 1 and type 2A fibres at high intensity running at above lactate threshold.  Similarly, in the case of humans, the study by Gibala and colleagues (J Physiol Vol 575, pp 901-911, 2006) suggests that high intensity training is the most efficient for producing increases in muscle oxidative capacity.

Although the evidence suggests that the most efficient way to increase capillary density and number of mitochondria in skeletal muscle in the short term is via fairly high intensity running (above lactate threshold) there is no clear evidence that the benefit of such high intensity training continue to accumulate over a period of several years.  I am not aware of any systematic scientific studies that have compared groups of athletes undergoing different training regimes extending over several years. 

There are very few elite athletes who are reported to have shown continuous improvement over many years of predominantly high intensity training.  Individuals such as Gordon Pirie, who did a large number of high intensity interval sessions, had a relatively brief period at the top.  In 1956 he broke the world 3000m record twice, and won a silver medal in the 5000m at the Melbourne Olympics, but he never reached such heights again.  Emil Zatopek was a dominant force for somewhat longer winning a gold medal in the 10,000m London in 1948 and three gold medals in Helsinki in 1952, but it is probable that his famous high intensity sessions (e.g. 50×400m) were run at a relatively modest pace – perhaps around 10K pace – as reported in a comment on my blog by Ewen on 31^st March 2009 . 

In the absence of observational evidence, it is necessary to rely on our understanding of physiological mechanisms.  Potentially the most important issue is oxidative damage due to free radical production.  Both aerobic and anaerobic exercise result in the production of free radicals that have the potential to damage tissue, but provided the amount of exercise is not excessive, the body’s natural defenses can cope.  However both excessive intensity and excessive volume can result in the natural defenses being overwhelmed (Fisher-Wellman and Bloomer, Dynamic Medicine, vol 8, 2009, doi:10.1186/1476-5918-8-1)  In light of this evidence I think that the best strategy to produce continued improvement in aerobic capacity over a period of several years, is likely to be a compromise.  I plan to do an a moderate amount of interval training near to lactate threshold or a little above, but will balance this with an approximately equal amount of low to mid –aerobic running; and some non-demanding exercise focused on improving flexibility and proprioception.  

2) Increased capacity of the heart to pump blood.  Cardiac output is the product of stroke volume and heart rate. Unfortunately the decrease in maximum heart rate with age is one of the major contributors to deterioration in maximum rate of oxygen utilization with age, and there appears to be little that can be done to prevent this.  Stroke volume is determined by the difference between the volume of the left ventricle at the beginning and end of ventricular contraction (systole).  Similarly to the situation with training to increase aerobic capacity of muscles, the evidence indicates that high intensity interval training is the most efficient way to increase stroke volume.   The study by Helgerud and colleagues from Trondheim in Norway (Med Sci Sports Exerc. 39(4):665-71; 2007), which I described in some detail in my post of 23^rd June 2009 demonstrated that 4x 4 min of running at 90-95% HRmax followed by 3 min of active resting at 70%HRmax, 3 times per week for 8 weeks produces a greater increase stroke volume and also increase in VO2 max than the same number of sessions of either long slow distance running at 70%of maximum heart rate, or tempo running at around lactate threshold. 

However, as in the case of aerobic development of skeletal muscle, the goal of producing continuous development over a period of years must take account of the risk of free radical damage, and I think the same compromise program that balances intensity and volume, non-demanding exercise, and rest is likely to be optimal. 

3) Leg muscle strength and power:  Although I have never formally tested my leg muscle strength, I know from my reduced ability to step upwards onto a chair while carrying a heavy object  that my muscle strength has decreased with age.  My reduced stride length when sprinting confirms this loss of strength and power.  My current time for 100m is 18 sec. I never recorded a 100m time as a youngster, but could certainly run a 400m in much less than 60 sec, so I have clearly slowed down when sprinting and this is almost certainly due to loss of muscle power.  Running entails eccentric contraction of quads, hams and calf muscles.  However, developing eccentric muscle strength presents problems, because eccentric forces tear muscle fibres.  The most efficient way to increase strength of eccentric contraction is plyometric exercise, but the sharply applied stretching of muscles during plyometrics causes extensive damage, which is also likely to produce production of free radicals and a risk of long-term damage (Bloomer RJ & Goldfarb AH. Canadian Journal of Applied Physiology, 29(3): 245–263, 2004.)   Therefore, I will engage in weekly strength training, employing exercises that entail moderate eccentric stress, and very sparing amounts of plyometric exercise.

4) Neuromuscular coordination:  In recent years I have worked on developing a style of running that I believe is efficient and fairly safe – described in the pages ‘Running – a dance with the devil’ in the side bar of my blog.  This style is closely related to Pose, but I have tried to avoid what I perceive as the problems with Pose.  I have not yet focussed on applying this style to faster running.  In the near future, I will spend a session per week practicing this style of running at ‘near sprinting’ pace, but over short distances and with adequate recovery to minimize exhaustion. 

 

Other metabolic and musculo-skeletal developments

There are many other metabolic developments, such as increased ability to store glucose; to burn fats; to metabolize lactate, and musculo-skeletal developments such as resilience of connective tissues that I anticipate are best developed within the context of a comprehensive program focusing on the four key elements described above   

 

The program

I plan a periodized program comprising periods of several months duration within which I will spend several sessions a week focusing on the development of specific aspect of fitness, while maintaining a continuous background of aerobic development.  In addition I will spend one or two sessions per week on core strength, balance and proprioception.

Taking account the above considerations, here is my proposed program for the next 4 months:

 

Specific goal: increasing leg muscle strength and neuromuscular coordination.  The program will include the following sessions:

1) body-weight exercises that entail moderate eccentric load on the major leg muscles: hams, quads, gastrocnemius, soleus, peroneals, gluteals and tensor fascia lata (1/2 hour per week);

2) short hills (approx 90 seconds, 4-8 reps at  ¾ pace effort) on alternate weeks.

3) running style sessions:  mainly drills and short stride-outs focusing on a relaxed style.

 

Aerobic and cardiac development:

1)      Two interval sessions per week on the elliptical cross trainer.

2)      One long(ish) run: approximately 15Km at whatever pace appeals to me on the day.  I anticipate that these runs will mainly be progressive runs starting in the low aerobic zone and increasing to mid aerobic or upper aerobic zone for the final few Km, though on some occasions I will include 5-10 Km of fartlek within the 15 Km run.

 

Core strength, balance and proprioception

1)      body-weight exercises designed to improve core strength (1/2 hr per week)

2)      exploration of Yoga postures suitable for development of balance, flexibility and mental focus (1/2 hour per week)

This program entails 7 or 8 sessions of quite diverse content, per week, requiring a total duration of 4 ½ to 5 hours.  The amount of running in this 4 month period is intended to be modest, including one weekly 15Km run; a weekly running style session; and a short hill session on alternate weeks, while I focus on leg strength and neuromuscular coordination.  I anticipate that the most demanding sessions will be the elliptical interval sessions.   These will provide a substantial work-out for the cardiovascular system but due to the fact that the elliptical action involves no impact and relatively little eccentric contraction of leg muscles, the stress on the legs is relatively mild.

I will aim to do at least 80% of the scheduled sessions, but will occasionally substitute other activities such as hill walking, swimming, cycling or kayaking, as the opportunities present themselves

My provisional plan beyond this 4 month period is to devote 2 months to specific preparation for a 10K race in spring.  The major change will be the replacement of some of the elliptical sessions and strength sessions by interval and tempo running sessions.  Then during the summer of 2010, I will prepare for a half marathon in autumn.

High volume v high intensity, and long term plans

As the daylight hours shorten and we enter the final few weeks of autumn, I am thinking about goals for the coming months.  Looking back, it has been a frustrating summer.  A debilitating illness in June and July torpedoed my preparation for the Robin Hood half marathon in September. My eagerness to determine whether or not I could recover sufficient fitness by September led to a series of problems, the most serious of which was intense over-activity of my parasympathetic nervous system that clamped my maximum heart rate at around 142 bpm in mid-August.  On September 13^th, I lined up for the race in a seriously under-prepared state.  My aerobic fitness was not too bad, but I had not prepared my muscles for the rigors of a half marathon race.  Perhaps it was unsurprising that I tore a hip adductor while making a sharp turn across an uneven patch of roadway at about 6 miles.  I did manage to complete the 13.1 miles with a markedly shortened stride and virtually no airborne phase, in a time a little over 103 minutes.  I was pleased that I had managed to get to the finish, and I learned a few things along the way, but overall it was a very frustrating summer. 

Among the things the summer has emphasized is that acquiring aerobic fitness is only a small part of what is required.  If I am going to recover the ability to race at paces in any way comparable to the paces I used to run in my youth, after allowing for the effects of 4 decades of aging since that time, I need a long term plan.  I would like to run a good marathon again, but because I currently work about 50-60 hours per week, there is no possibility that I could do enough training to do justice to a marathon in the near future. 

I plan to reduce my working hours substantially in 2011.  So my goal is a ‘good’ marathon in 2012, but what could be described as a ‘good’ marathon?  Using the WAVA adjustment for age, my races of 40 years ago indicate that, all being well, I might be capable of a marathon time around 3 hours in my late 60’s.  However, several minor ailments which I have had since childhood and which caused minimal problems in young adulthood, have been much more troublesome since my fifties, so a 3 hour marathon is clearly out the question for 2012. For the time being I will set a provisional target in the range 3:15 to 3:30, and refine this target more precisely in light of what appears plausible as 2012 approaches. 

How should I prepare myself?  The major debate in endurance training is the debate between focus on high intensity and high volume training.

 

High intensity

The father of high intensity training was the German coach and cardiologist, Woldemar Gerschler, who developed the concept of interval training: bursts of anaerobic activity separated by brief recovery epochs.   This approach led in a fairly direct path via coaches such as  Franz Stamfl, to Roger Bannister’s demolition of the 4 minute barrier for the mile in 1954.   The parallel development of a similar approach led Emil Zatopek to gold medals in the 5000m. 10,000m and marathon in Helsinki in 1952, though it might be argued that Zatopek combined high intensity with high volume. 

More recently, the Furman Institute have developed a program based on only three running sessions per week entailing high intensity with modest volume.  The Furman program is supported by scientific evidence about the most efficient way to enhance aerobic metabolism, and the studies performed by the Furman Institute provide clear evidence that the program works in practice.  In an article in Runners World in Feb 2006, Amby Burfoot, reported that 15 of a group of 25 amateur runners who undertook the Furman program in preparation for the Kiawah Island Marathon while maintaining their usual commitments to jobs and family, set personal best times.

The paces specified for the three weekly runs in the Furman program: an interval session; a tempo session; and a long run, are all very demanding.  My own judgment is that the program places a little too much emphasis on aerobic development and not quite enough on development of endurance, but I have no doubt that for a runner with the determination to adhere to the program, it offers a good prospect of achieving the target time.  At first sight, the demanding paces might appear to carry a substantial risk of injury.  However, the fact that there are only three running sessions per week provides a fairly generous amount of time for recovery between sessions, thereby minimizing the cumulative fatigue that predisposes to injury.  In the Runners World article, Amby Burfoot reported that there was only a modest injury rate among the group of 25 runners in the Furman marathon study in 2004.   Injury forced one to withdraw from the program, and minor injury led three to drop from the marathon program to the half marathon program.

Because I think the Furman program does not place enough emphasis on endurance, I consider that it is only a useful program in the final four months of preparing for a target race once a sound base has been established.  I do not consider it is suitable  as the mainstay of a three year campaign, though I will reconsider it as I prepare for a few targeted half-marathons along the way.  I might consider a modified version of the program in the final phase of the campaign in 2012  but perhaps I should not make too many assumptions this far in advance 

 

High volume

The father of the high volume approach was Arthur Lydiard.  He promoted periodization of training with the major emphasis on the base building period, in which most the important feature was running about 100 miles per week at ‘a good aerobic pace’.  The spectacular tally of Olympic gold medals by Lydiard’s protégés, Peter Snell (800m, Rome 1960; 800m and 1500m, Tokyo 1964); Murray Halberg (5000m, Tokyo 1964), Lasse Viren (5000m. and 10000m, Munich 1972); and Pekka Vasala (1500m, Munich 1972) leaves little doubt that Lydiard’s approach can be extremely effective.  

More recently, coaches such as Hadd have reformulated Lydiard’s approach for an era in which heart rate monitors have facilitated a scientific approach to high volume training.  While Hadd’s approach is based on the sound practical foundation developed by Lydiard, and incorporates some sensible suggestions about using the HRM to monitor progress, ironically, his science appears to be based on a mis-reading of the scientific literature.  He appears to have mis-interpreted Dudley’s studies of rats (’Influence of Exercise Intensity and Duration on Biochemical Adaptations in Skeletal Muscle,’ Journal of Applied Physiology, vol. 53, pp. 844-850, 1982).  Dudley subjected laboratory rats to 8 weeks of training involving running on a treadmill 5 times per week at various intensities and for various durations.  He measured the increase in cytochrome oxidase, a group of enzymes located in mitochondria, that catalyze the final steps of oxidative metabolism.  The amount of cytochrome oxidase provides a good measure of aerobic metabolic capacity. Examination of Dudley’s data clearly demonstrates that the gains in aerobic capacity increased with increasing intensity of training up to VO2max, not only in muscles dominated by fast twitch fibres, such as white vastus, but also in muscles with predominant slow twitch fibres, such as soleus.  It is only at supra-maximal intensity levels above VO2max that there is any evidence of a lesser rate of improvement in aerobic capacity with increasing intensity.  Furthermore, at these supramaximal levels the total duration of training was less, and the lesser improvement in aerobic capacity might reasonably be attributed to decreased duration of running rather than inhibition of aerobic development.

It is not only evidence from studies of rats, but also the majority of evidence from studies of humans demonstrates that training intensities in the range between the anaerobic threshold (at which lactate accumulation accelerates) and VO2max (beyond which heart rate does not increase despite increasing power output) are effective for improving aerobic capacity.  In the study by Gibala and colleagues comparing 6 sessions of high intensity sprint cycling consisting of 4 to 6 30second sprints with 6 session of endurance training consisting of 90-120 minutes of cycling at 65% of VO2max, over a two week period, similar improvements in performance; muscle oxidative capacity; muscle buffering capacity; and muscle glycogen content were produced even though the total training time commitment was only 2.5 hours for the sprint training compared with 10.5 hours for the endurance training (J Physiol Vol 575, pp 901-911, 2006). Unfortunately, Hadd’s interpretation of Dudley’s data appears to have contributed to a fear among his disciples that exceeding lactate threshold during training will damage the development of aerobic capacity.   I believe this fear is unfounded.

It is also important to note that both Lydiard and Hadd advocate that a substantial proportion of training should be near the upper end of the aerobic zone.  Lydiard refers to running at a ‘good aerobic level’ and recommends the use of three different intensities that span the aerobic range, with several runs a week at the highest of these levels – a pace he designates as  ¾ pace.  As discussed in my post on 9^th April 2009, Lydiard’s ¾ pace corresponds approximately to lactate threshold pace.  Similarly, except in weeks in which the weekly mileage is increasing substantially, Hadd typically recommends two runs per week at heart rate that is about 10 bpm below the lactate threshold value.  While I think that Hadd’s science is questionable, I think that in practice, many of his recommendations for training have great merit.

 

How do African runners train?

The current dominance of African runners, including Kenesa Bekele, world record holder for the 5000m and 10,000m, and Haile Gerbselassie, world record holder for the marathon, suggests that they must be training effectively.  It is probably simplistic to assume that all African distance runners train similarly, but nonetheless, the bulk of the evidence suggest that many do a large amount of their training at a pace near to lactate threshold.  In a study comparing black South African runners with whites, Tim Noakes and colleagues found that the black and white runners had similar average weekly running volume (60 miles per week) but the black runners did 36% of their running at  above 80% of VO2max, while the white runners did only 14% of their running above this level (Journal of Applied Physiology, vol. 75, pp.1822-1827, 1993).  However it was not simply a matter of the black runners trying harder.  The black runners produced lower levels of lactate when running at a specified intensity.  Most notably they exhibited 32% lower blood lactate concentration when exercising at VO2max.  Furthermore, they were able to sustain an isotonic contraction at 70% of maximal force for about twice as long as the white runners, despite having a similar proportion of high endurance type 1 (slow twitch) muscle fibres.  This suggests that they had a much greater degree of development of the aerobic capacity of their type 2A fibres.   In my mind, the most plausible explanation is that many years of running at paces in the upper aerobic zone had produced great development of aerobic capacity, especially of type 2A fibres, allowing them to maintain training paces at or above 80% of VO2max without undue stress.

Thus, it appears that African runners dominance is due at least in part to doing a higher proportion of their training  at fairly high intensity (eg 80% of VO2max), but there is an important caveat: the African runners produce a lower level of lactate when training at high intensity.  This is consistent with anecdotal reports that elite African runners train hard but avoid remorselessly punishing their bodies.  Furthermore, anecdotal evidence suggests many have been running since childhood and it is likely that this has provided a crucial foundation.  It might be dangerous to assume that a runner with only a few years of regular training could safely do large volumes of training near to lactate threshold.

 

So which is better: high intensity or high volume?

It is clear that both high intensity and high volume approaches can produce improved aerobic capacity. In a runner with moderate baseline fitness but under-developed aerobic capacity, either approach will lead to improved performance.  Perhaps the most important issue is avoiding injury.  The high power output required for high intensity running places great acute stresses on muscles, but cumulative fatigue associated with high volume training can result in failure to mount a well integrated reaction to an unexpected jolt, and lead to tearing of an already exhausted muscle.  Looking back over the years, I can attribute approximately the same number of muscle injuries to inadequate preparation for increase in volume as to inadequate preparation for increase in intensity.    

At elite level, the distinction between the programs lessens, as the choice is between high volume with fairly high intensity (eg a substantial proportion at tempo runs at 80% of VO2max) on the one hand, and fairly high volume including a substantial number of high intensity interval sessions, on the other.  Either of these options is probably only feasible for individuals with a very well established base level of fitness.  The evidence from laboratory studies suggest that aerobic fitness can be increased most efficiently by training at high intensity, and therefore a program with a substantial number of anaerobic interval a sessions is probably the most efficient way to increase aerobic fitness.   However, while aerobic fitness is crucial for distance running, it is not the only thing that matters.  The current dominance of African distance runners suggests that high volume at fairly high intensity (eg mainly near lactate threshold) might be preferable, though my own opinion is that years of running, starting in childhood, is the major factor accounting for the success of African runners.

 

My own younger days

I was never an elite athlete, although I suppose I could have reasonably described myself as a sub-elite marathon runner, with my best times in the range 2 hours 20 min to 2 ½ hours.  Perhaps surprisingly I have no precise record of my best races, maybe because I did not consider myself a serious athlete.  During my running ‘heyday’ I was actually more interested in mountaineering.  Insofar as I trained systematically at all, I aimed to run moderately large volumes (occasionally up to 100 miles per week) at a ‘good aerobic pace’.  I used to consider that there was little point in running any slower than 6 minute mile pace.  I preferred to spend my time walking in the hills or climbing mountain rather than running slowly.   So perhaps my training could be classified as Lydiard style though I rarely did the high volumes recommended by Lydiard.  On the other hand, I did some tigerish hill walking and mountaineering.  The other point to note is that like some of the Africans, I ran to and from school as a youngster, and during my teens, I simply regarded running as a normal form of locomotion.  I also played a lot of football and basketball.  But that was a long time ago.

 

The risks of too much training

Not only does training present a risk of acute injury but also a risk of overtraining.  There are two forms of overtraining : the sympathetic and the parasympathetic.  These are characterized by impaired performance accompanied by psychological a features such as fatigue and low motivation; together with a complex array of abnormalities of the autonomic nervous system and hormonal function.  As discussed in my post of 29^th June, one of the most thought provoking aspects of over-training is the possibility that it is associated free radical damage arising from the failure to re-cycle ADP.  

The high energy molecule, ATP (adenosine triphosphate), is the immediate source of the energy that drives muscle contraction.  It is a molecule consisting of a purine (adenine) and a ribose sugar molecule  linked via high energy chemical bonds to three phosphate groups.  When ATP is harnessed to drive muscle contraction, it is split to produce ADP (adenosine diphosphate) and a phosphate ion.  Most of the ADP is re-cycled in the process of regenerating ATP in the final stage of either aerobic or anaerobic metabolism.  However, a proportion of the ADP is not recycled, but instead is degraded to uric acid.  The process of degradation of ADP generates free radicals – very reactive molecules that can damage muscle tissue by oxidation.  Such damage would be expected to have long-lasting effects, and perhaps even be irreversible, especially in the older runner.

The facts regarding free radical damage remain uncertain.  There is ambiguous evidence regarding the benefits of anti-oxidant supplements.  However, after weighing-up the various strands of evidence, I am inclined to believe that for the runner who wants to continue to enjoy running into old age, one of his or her maxims should be to train as little as is necessary to achieve his or her goals.

 

The challenge

Thus, I am on the horns of a dilemma.  I believe that the successes of contemporary African distance runners, and perhaps even my own modest successes as a marathon runner four decades ago, were based on the cumulative benefits of many years of vigorous exercise.  Yet, there is also a body of evidence suggesting that excessive training might ultimately result in long term damage.   I am therefore going to have to make some shrewd judgments in the design of my campaign to yet again run a creditable marathon and to continue to enjoy running for many years after.

In the past few weeks I have been doing a lot of thinking about this challenge, and I have almost completed crafting my plan – a plan that will no doubt require adjustment as the years go by.  It is a plan that entails periodization.  Every period will include ‘foundation’ activities designed to promote continuous development of blood vessels supplying heart and leg muscles, and the development of the aerobic capacity of type 2A muscle fibres, as I believe that both of these adaptations are an essential foundation for engaging in moderately high intensity training without subjecting the body to remorseless stress.  Each period will also have a specific focus.  The specific focus of the first period will be improving the strength of my leg muscles. 

In my next posting I will provide an outline of the overall plan for the campaign to run a good marathon in 2012, together with a more detailed account of the plan for phase 1.

Five strategies for training a runner’s brain

In recent weeks I have been exploring ways of training my non-conscious brain to relax its apparently over-protective control of my cardiac output.  I think I have been successful, though at the price of straining a muscle – it is very difficult to get everything right.  Nonetheless, I am sufficiently encouraged by the gains to examine the way in which similar principles might be applied to other aspects of running.  The underlying principles that I have been employing are the principles of cognitive behavior therapy (CBT).  This is a form of therapy that has been widely used in recent years for treating a range of minor mental problems; some enthusiastic advocates see it as a technique for dealing with all sorts of everyday challenges.  In reality, panaceas don’t exist, but because some of the principles mesh with the growing evidence about the role of the brain in shaping our running, it is worth a closer look

 

Cognitions, behaviour and childhood development

CBT is a form of psychological therapy that deals with practical problems in the here and now, and  is often regarded with distain by psychotherapists who believe that change in human emotions and behavior is best achieved by dealing with deep rooted maladjustments that have their origins in early childhood.  It is almost certainly true that childhood experience shapes both our minds and our bodies – more striking than the genetic endowment of elite African distance runners is the observation that many of them ran to and from school every day in early childhood.  As someone who also had the good fortune to run to and from school each day for several years, I suspect that the long-term benefits were not merely increased development of heart and leg muscles, but also arose from both conscious and non-conscious memories. 

 

There is little evidence that it is effective to try to change the consequence of childhood development by regression to childhood.  That is the tortuous path mapped out by Woody Allen in his depictions of neurotic New Yorkers dependent on weekly visits to their therapists.   In contrast, CBT is short term and problem oriented.  There is good evidence that it works for treating depression and anxiety.  Of course when testing the effectiveness of psychological treatments, it is impossible to employ a ‘gold standard’ double blind controlled trial in which neither therapist nor patient know whether the patient is getting the treatment under test, or an inert comparison (placebo).  However the evidence from fairly well controlled but non-blinded studies does show that CBT works for mood disorders, and has efficacy similar to that of antidepressant medication (see for example the review by Cuijpers and colleagues, J Clin Psychiatry. 69(11):1675-85, 2008)  

Can the same principles be used to get the best out of our non-conscious brains when we run?  The core principle of cognitive therapy is that our conscious thoughts often involve us jumping to self-defeating negative judgment about ourselves that lower our mood and paralyze our performance.  That is the C part of CBT.  Just as important in the B part.  B denotes behavior therapy.  Thirty years ago, behavior therapy alone was in vogue.  It was a way of changing behavior based on observations of the ways in which laboratory rats or dogs can be trained. 

 

Similarities and differences between humans and other animals

The studies of animals demonstrated two common types of learning: Pavlovian conditioning which entails learning to respond to a new stimulus by associating it with an established stimulus that has an automatic effect (eg the smell of food producing salivation); and Skinnerian conditioning: learning a new pattern of behavior as a result of rewards for small steps in the right direction.  Skinnerian conditioning works well for training rats, and in fact can also be used to train humans, but pure behavior therapy went out of fashion as a form of psychological therapy, except for young children, for two reasons.  It does not fit well with contemporary society’s belief about the importance of being in charge of decisions about ones own life.  Secondly, and perhaps more importantly, it fails to utilize one the amazing things about the human mind and brain: our ability to make conscious decisions based not only on immediate rewards, but also on memories of the past and on plans for the future.

 

CBT attempts to incorporate conscious evaluation, planning and decision making with the type of automatic learning processes that work well in other animals.  In principle this makes sense: all of the basic building blocks of the human brain can be found in the brains of other animals and it is therefore likely that training strategies that work for rats in the laboratory, might also work for humans.  But despite being built of the same building blocks as the rat brain, the human brain has an immensely richer network of connections between the building blocks, and the richness of these connections endows us with what we experience as the ability to make conscious decisions.  But sometimes conscious thought can get in the way.

 

Pacing ourselves

In the domain of running, one of the unanswered mysteries is how we pace ourselves during a race.   It can scarcely be dependent entirely on conscious memory from previous races, but neither can it be a process of pushing our bodies to the limit throughout the race.   Tim Noakes and colleagues have developed the concept of the central governor which regulates effort by anticipation that is based at least in part on non-conscious processes.  The central governor hypothesis remains a hypothesis that has generated heated debate for almost 15 years.  So far, the studies designed to provide direct support of the hypothesis have not been convincing.  For example, the claim by Ross Tucker and colleagues from Noakes’ lab in Capetown that the rate of heat storage mediates an anticipatory reduction in exercise intensity during cycling (J Physiol 574: 905–915, 2006) has been criticized by Jay and Kenny on the grounds that the method of estimating the rate of heat storage was flawed (J Appl Physiol 107: 630-631, 2009). However, failure of experiments to establish the truth of the hypothesis does not prove that the hypothesis is invalid –the complexity of the human mind and body makes it difficult to obtain convincing evidence.  Nonetheless, there are many observations about the pacing of human performance that are difficult to explain by any hypothesis other than some form of anticipatory regulation, which is at least partly non-conscious. 

 

My own conclusion is that the central governor theory is a good framework for developing ideas, but the ideas must be tested out against experience.  Of course, many of the ideas that emerge from speculation based on science are things that our grandmothers might have told us – but if I had listened only to my grandmother, I would have given up running long before my mid sixties.  We now know enough about how the brain and mind works to justify trying to fit our own experience into a coherent framework, even though the immense complexity of the mind and brain means that the details are speculative and predictions need to be interpreted cautiously. 

 

So let us start by looking at the implications of principles that underpin CBT: First is the behavioral principle what is rewarded (for example, by success) will be reinforced by non-conscious mechanisms and become a part of our behavioral repertoire.  Second is the principle that cognitive responses shape human learning, but that our automatic cognitions are often self-destructive, and need to be tested against reality.  These two principles provide the basis for understanding some of the conscious and non-conscious mechanisms by which our brains set the pace when running

 

Five strategies

Here are five strategies that I have learned by testing my experiences against the general principles listed above.  All of these have no doubt been advanced previously by runners and coaches, purely on the basis of what experience has taught them, but over the years I have met coaches and runners who have expressed notions counter to these ideas – so at least for me, having a theoretical framework allows me to assemble a repertoire of training strategies that provide a coherent guide but nonetheless that I take with a pinch of salt:

 

1) Race often: racing is the best way to demonstrate to your brain just what your heart and skeletal muscles are capable of.  The excitement of the race maximizes dopamine release in the brain, and adrenaline release elsewhere in the body.  High dopamine levels (the principal  mediator of motivation) strengthen the signals the brain sends to the muscles; high adrenaline promotes strong contraction of heart muscle and efficient distribution of blood to the muscles.  So a race that is fairly hard but not totally exhausting race can be a great way to bring yourself to a peak.  However, it is essential to provide adequate time for recovery from the short term damage to muscles that racing produces.

 

2) Frequently run faster than target race pace in the sharpening- up phase, either by running shorter races, interval sessions or fartlek.  This teaches your brain that you still have plenty in reserve at race pace.  On the other hand, I do not regard ‘over-distance’ sessions as especially useful from the point of view of mental preparation.  Ever since childhood I have had a deeply embedded confidence that, barring a serious muscle injury, I can last the distance in any race; so at least for me, the more challenging issue is whether or not I can sustain the target pace.   Perhaps each individual needs to identify their own mental vulnerabilities.

 

3) Maintain conscious focus on the present:  In the mid stages of a long race, conscious focus on the distance remaining can undermine confidence of ones ability to sustain the planned pace.  Although pace judgment in a long race requires a sophisticated calculation by the brain, it is often better to leave the micromanagement of pace to the non-conscious brain.  When you focus purely on the sensations of breathing and the rhythm of running without consciously questioning how long you can sustain this, a fast pace often feels more exhilarating than daunting.  On the other hand, insidious negative thoughts can be destructive.

 

4) Make the most of bad days: When you body tells you that it cannot cope with a planned training session, it is generally better to aim to sustain the intended pace or even build up to a slightly faster pace for a shorter period; or maybe do some stride-outs at target race pace, but without forcing yourself; the aim is to demonstrate that there is a bit more in the tank than your brain believes, but not to wreck yourself.

 

5) Use you conscious brain to keep things in perspective: do not catastrophize if you have a bad session; make a mental list of the positive features of the session; be aware that the body has immense capacity to compensate for short-term minor disruptions, such as poor sleep; suboptimal food or fluid intake; minor injury – and accept that it is OK to stop if you have a definite injury – or to pause to deal with increasing local tension in a muscle.

Fatigue is a complex thing

I have been pre-occupied with fatigue in recent weeks, but I think that is now behind me.  For me, the most interesting thing as been the fairly clear evidence from my heart rate recordings that my non-conscious brain imposed a limit (mediated by the parasympathetic nervous system) on how much work my heart was able to do.   While I think that limit was initially based on a non-conscious but sensible protection strategy, it eventually because over-protective.   Furthermore, I think it is likely that my conscious strategy of graded exercise to teach the non-conscious part of my brain that regulates the autonomic nervous system, that it was safe to relax the limit, allowed me to recover fairly rapidly.

Ironically the final test of my recovery strategy was at the price of thrashing my legs beyond their current ability to cope in the Robin Hood half marathon.  So I am now nursing strained hip adductors.  However they are recovering. The bruising that tracked down the medial aspect of my thigh from near the point where adductor longus attaches to the femur has now turned yellowish-purple. In the past two days I have done very gentle runs of around 6Km without any sign of fresh bruising.  However it has been noteworthy that my legs are still tired, confirming that the adductor strain was merely a crunch that might have easily struck in any of the other major leg muscles.  In some ways I am pleased it was the adductors because shortening my stride allowed me to continue with relatively little further damage.  Maybe a tear of the hamstrings or quads would have stopped me from doing any further damage, but on balance, I am really pleased that I was able to finish.    For the next week or so, it will be gentle exercise to promote recovery while trying to avoid tearing the healing fibres apart.

 

Fatigue is a complex thing

While it appears that the parasympathetic action of the heart was the mechanism of my recent fatigue, I suspect that many instances of the more transient fatigue that sets in during long races are mediated by other mechanisms, especially by mechanisms that act directly on the leg muscles. 

One of the great things about the blogs by amateur runners is the insight they provide into what goes on in the mind and body during a long race.  I am cautious about expressing my thoughts about other people’s blogs in my own blog, but overall, I consider that what people have freely put into the public domain is legitimate material for comment.  I am therefore inclined to put down my speculations about the report on the Dingle marathon a week ago, by Thomas (Diary of a Rubbish Marathon Runner, http://rubbishrunner.blogspot.com/) though I should start with the caveat that my speculations  say more about me than about Thomas.  Nonetheless I will let Thomas know that I have written about him so he can correct any mis-perceptions on my part.

Thomas’ experience is especially informative because he is one of the most determined and motivated of those runners whose blogs I follow. Therefore I think it can be taken for granted that a far as conscious determination goes, few runners would approach a race with more dedication and determination than Thomas approached the Dingle marathon.  As the event unfolded, I think he ran an excellent race; his time and placing are, beyond doubt, great achievements.  He did not achieve a personal best, and one does not need to look far for the obvious explanations: an unseasonably warm day, and a brutal hill in the final few Km of the race. 

However, if one approaches the evidence with a mental bent towards understanding how it was that these two circumstances influenced Thomas’ race, several more intriguing thoughts arise.  

Background

But first we need to look at the background.  Thomas achieved 3:05:37 in the Dublin marathon last year and has trained very hard and very effectively since then.  He ran a creditable 3:10:36 in Boston under difficult conditions in April this year.  As he approached Dingle, his training paces demonstrated that he had the potential for a sub- 3 hour marathon under favorable circumstances.

At Dingle, circumstances were not favorable.  After miserable weather through July and August, Saturday 12^th September proved to be one of the most glorious days of summer for anyone except a marathon runner.  The temperature in Dingle was 22 degrees C (72 degrees Fahrenheit). 

Acclimatization to warm weather

There is no doubt that humans acclimatize to warm weather, though having spent my childhood in Adelaide, South Australia, I have often wondered about the mechanism of acclimatization.  Adelaide has cool winters and warm summers.  In early spring, when the temperatures first exceed 75 degrees Fahrenheit (we used the old units in those days) it felt great, but almost too hot for comfort.  A few months later,  we considered that we were being cheated of our summer if the temperature was not regularly in the upper 80’s or low 90’s,  and as children, we even took a perverse delight in times when the daily maximum temperature exceeded 100 degrees for several days on end.  I often trained in temperature well above 90 degrees and thought nothing of running a 5000m race on a mid-summer afternoon.

What had changed between the first days of spring and mid-summer only three months later?   There might have been changes in the function of our kidneys or sweat glands, but I suspect that the main change had been a change in what our brains accepted as normal. 

Jim Peters and Il Topolino

So what happens when we race on hot days?  Probably the winner of a long race on a hot day is the runner who is best acclimatized, but what does acclimatization entail?  Jim Peters’ collapse only yards from the line in the Vancouver marathon in 1954, while miles ahead of his rivals, suggests that the reason he was so far ahead was not due to a greater ability of his body to withstand heat, but rather an ability to over-ride his brain’s attempts to keep his body temperature within safe limits.

Don Thompson’s gold medal in the 50K walk in Rome in 1960 provides another thought provoking illustration.  Thompson, who was nick-named Il Topolino (‘mighty mouse’) by the Italian crowds, was diminutive in stature but mighty in his spirit.  He had trained for Rome in an improvised hothouse in the bathroom of his mother’s house in Middlesex.  He installed a stove in the room and put on a kettle to boil; closed the door and window; and switched on the electric wall heater to augment the effect of the steaming kettle.  Years later, when asked how Paula Radcliffe should prepare for the marathon in Athens in 2004 his reply was: ‘I trained in the bathroom about three times a week, from May to September, but I didn’t stay in there long each time and I think it was more about a boost to my confidence.’  Maybe Il Topolino had trained his brain to believe that keeping up the pace when the temperature was above 80 degrees F was possible, rather than adjusting the function of his kidneys or sweat glands.

The scientific evidence

Scientific studies confirm athletes tend respond to hot weather by slowing down to minimize the rise in core temperature; rather than by slowing down once core temperature has already risen.  In a comparison of African and Caucasian runners during self-paced 8K treadmill runs performed under cool and warm conditions, Marino and colleagues found that both groups ran at similar pace in the cool conditions.  The Caucasians ran more slowly under warm conditions, but sweated more profusely and maintained similar body temperature.  Marino concluded that the observation that the African runners ran faster only in the heat despite similar thermoregulatory responses to those of the Caucasian runners suggests that the larger Caucasians reduced their running speed to ensure an optimal rate of heat storage without developing dangerous hyperthermia (Marino et al., J Appl Physiol, 96: 124-130, 2004).

The diminutive Il Topolino demonstrated in Rome that it is possible to train the brain to over-ride this mechanism, but the case of Jim Peters in Vancouver perhaps illustrates that it can be difficult to get the balance right.  Fortunately, Peters recovered quite rapidly after re-hydration.

Back to Dingle

So what happened to Thomas at Dingle?  The temperature was warm by Irish standards, but in fact not really all that hot, at least by Australian standards. However, Thomas had been training in cold and windy weather around the shore of Caragh Lake in Kerry.  To both his conscious and non-conscious brain it seemed hot.  Nonetheless, he started with a first mile of 6:51, almost exactly in line with his 3 hour target pace and he reports that first few miles went very, very well. He was running  easily, feeling relaxed and happy.  For much of the first half, the race continued to go very well.  He was holding a pace of around  7:05 pace per mile which would have given him a finishing time near to his PB of 3:05:37.  However, it is of interest to note from the traces he presents in his blog that has pace tended to slow slightly throughout the first half, and his heart rate to fall very slightly from a mean around 168 bpm between miles 1 and 3 to a mean around 166 bpm from miles 10 to 13, despite greater undulations in the course after 6 miles.   Was his brain, either consciously or unconsciously, protecting him from undue exertion?   He reported that at 10 miles he started to feel some signs of fatigue.  Nonetheless he was still running well until mile 19, when the pace record shows he ‘lost it.’ He slowed from a pace of 7:10 per mile around mile 18 to slower than 7:30 per mile around mile 20.  The undulations in the road make the precise figure irrelevant but there was a definite trend towards slowing despite a net fall in altitude of approximately 50 feet between mile 18 and mile 21. 

Something else was looming on the horizon.  He reports that as he approached the drinks station at mile 21 he ‘could see the mountain looming ahead. It reminded me very much of Connemara’s “Hell off the West”, and I was in no illusion about the task ahead. This was going to be tough’    Starting in the 22^nd mile the road ascended 300 feet, at times with an incline of 13%.  He struggled gamely to the top, but shortly after the summit he was pole-axed by cramp.  His blog provides a graphic description of the pain in his calf muscles.  After a few protracted and excruciating moments he managed to apply a counter-tension that relieved the cramp, and he finished with an exultant wave to the crowd in 12^th place in a time of  3:12:44.   

It was a great performance, and I think it is unlikely that Thomas could have done any better on the day.  It is probable that some physiological process such as electrolyte imbalance was the coup that pole-axed him on the final hill, but his prospects of a PB were gone by 21 miles.  At that stage his heart rate had already fallen below 165.  We do not know how much his body temperature had risen, but Marino’s study suggests it unlikely that it had risen to dangerous levels.  More likely, his brain was protecting him from the heat and from the mountain ahead.  Some non-conscious part of that brain was probably also aware of his electrolyte status, and integrated this information with the message from his conscious brain that things were about to get very tough.  

While it is unlikely that there was anything Thomas could have done to have overcome the sensible response of his non-conscious brain at that time, no matter how determined he was, I suspect that if he had trained in an improvised hot-house, as Il Topolino had done almost 50 years previously, his brain might have allowed him to sustain a faster pace between 3 and 21 miles.  But whatever the physiological limit proved to be – electrolyte disturbance, core temperature or something else, it is probably just as well that his brain did not allow him to run himself to a state of exhaustion in Dingle.  That wasn’t the right day or place for a PB.  His more recent blogs indicate that he is recovering rapidly, and after a two week recovery phase, he is about to begin his preparation for the Dublin Marathon in 5 weeks time.  I think there is a very good chance he will record a PB in Dublin, and if the weather is good, his goal of a sub-3 hour marathon is within reach.

Half-marathon reminiscences

The first question on Monday morning was whether or not the previous day’s half marathon had triggered a relapse of the fatigue of the previous few weeks.  I was delighted to find that Monday’s orthostatic test was a textbook illustration: a 9.8 bpm rise in heart rate from resting to standing , with a healthy shift from parasympathetic preponderance while resting towards a sympathetic preponderance while standing.  In the subsequent two days the orthostatic test has continued to yield similar results with orthostatic rises of around 8 bpm.  I still feel tired, but I think this is normal tiredness after pushing my legs a bit harder than my training had prepared them for.  I appear to have overcome the troublesome fatigue that had hamstrung me when I attempted to recommence training after my illness.

The second question was: how serious was the strain of my left hip adductors that had developed midway through the half-marathon?  On Monday morning there was a dull ache in my upper thigh, and I made no attempt to test the situation any further.  Tuesday evening I did a short easy session on the elliptical cross-trainer without exacerbating the problem, so this morning, I did some cautious hip swings.  I found I could swing the left leg to 90 degrees without trouble.  On the right, I could swing only to about 60 degrees without pain.  The task of preventing rotation of the pelvis when swinging the opposite leg places greater demands on the adductors of the stance leg, so this was not surprising.  I was sufficiently encouraged to try an easy run this evening.  However as soon as I started to jog, the pain returned so I stopped immediately.  The adductors need a few more days of rest, but I am hopeful I will be running again before too long. 

Although my primary goal on Sunday was to test my recovery from fatigue, it was not all about watching the heart monitor.  A few photos from the final stages give a glimpse of some of the other features of the run.

 

In the first picture, on the left, taken about 120 metres from the finish, I am managing to maintain reasonable form.  But with the limited swing of my right leg, a firmly anchored left foot and short stride, I certainly do not look as if I am racing.   The second photo, about 80 metres from the line, shows that despite my short stride and almost non-existent airborne phase, the gap separating me from a runner from Redhill Road Runners (7484) is closing.  The picture catches me relatively late in the swing of the left leg.  There is visible tension in my hip adductors.  At this stage of the gait cycle the main role of the hip adductors is to assist the extensors in arresting the swinging leg and bring the foot backwards relative to the torso.  On account of my feeble swing, that should not have required much muscle power.  I presume the overt tension reflects a mild spasm due to torn fibres.

However it was the next picture that brought back a bit of nostalgia for times past. In the few long races I have run since recommencing running in middle age, I have let the lingering remnants of the competitive spirit of my youth to have free rein in the final kilometer or so.  If two runners are shoulder to shoulder after 20Km, they are likely to be fairly evenly matched and it is usually the one with a bit more fire in his belly who crosses the line first.  But wisdom had dictated that Sunday’s run was not an occasion to let the competitive spirit go wild.  About 1Km from the end, a runner in the yellow vest of the Steel City Striders strode past me and I simply let him go without a challenge.  However here I was, within a few metres of the finish, and it was just too much to let this opportunity go by.   

If I half close my eyes looking at the picture I can almost imagine myself forty years ago – well maybe I would need to put on very dark glasses and well as half-closing my eyes to create that illusion – but at least it looks as if I am racing.  I did retain enough sense to avoid an all out sprint, and was content to cross the line a second or so ahead of my rival from Redhill.  I also overtook the young man to the right of the second photo (4184) and a young woman who is not in the field of view.  So although I had not intended to treat Sunday’s run as a race, it was good to have a brief reminder of times past.