Base-building for a half marathon/marathon

I need once again to re-build my aerobic base.   Last year, I enjoyed a year free of ill-health, and after averaging a little over 40 miles of predominantly low aerobic training each week in the spring and summer, was pleased to run half marathon in 101:50.  By mid-summer it appeared that I was mainly limited by lack of strength rather than aerobic fitness.  Therefore, following the half-marathon, I began regular resistance sessions: three sessions per week in which the major focus was on 5 sets of 5 squats with the goal of building up my 5 RM to at least 150% of body weight.  Although I did not know it at the time, Alberto Salazar had set a very similar target for Mo Farah in preparation for the London Olympics.  Mo achieved a 5 RM of 200lbs for squats.  My program of lifting went well, and to my amazement, I built up to a 5 RM of 230 lbs over a period of four months.  Since I am a little lighter than Mo and substantially more than twice his age, I felt quite pleased with my progress.  I am afraid that I will no longer be able to blame my atrophied elderly muscles for my poor running speed.  Furthermore my creaky joints appeared to cope with the lifting well.  By the end of the year I had less arthritic pain than at any time in recent years. So I was looking forward to redirecting my focus onto running in the new year

However, shortly after I started running again, my former arthritis returned.  As on previous occasions, the problem started in my neck and left wrist, before extending to my knees, so I do not think it can be attributed directly to the impact at foot-strike when running.  I do wonder whether running led to a build-up of circulating inflammatory molecules in the blood stream that inflamed the joints, but that is speculation.  The unfortunate consequence was curtailed training and loss of fitness.  In recent weeks, my joints have settled and now only my neck is painful – though my knees still feel fragile.  But my endurance and aerobic capacity have deteriorated.  I have deferred my target of a sub-100 minute half marathon in the spring to the autumn.

So once again I am facing the cardinal question: what is the best training strategy for base-building?  For an endurance runner, a sound base has two key components: resilience of the connective tissues (ligaments, tendons, bones, fascia) and ability to utilise fuel efficiently.   The simple rule of thumb for building up resilient connective tissues is a gradual increase in volume and intensity of training over a sustained period, though there is a paucity of detailed information about this topic.   On the other hand, there is abundant information about the topic of improving the efficiency of fuel utilization, but some crucial issues remain a topic of debate.

The major determinant of endurance running performance is the maximum pace that can be sustained without accumulating appreciable lactic acid.  Loosely speaking, that is the pace at lactate threshold.  The problem with this terminology is that there is no precise threshold. Although lactate level in the blood begins to rise fairly rapidly after a certain point, the graph of lactate concentration against pace does not show a single sharp kink between two straight lines. Instead there is an initial upward trend typically occurring at a lactate concentration above 2mMol and then a steeper up-slope beyond 4 mMol.   From the practical point of view, there are two fairly clear thresholds.  The first corresponds to maximum pace that can be sustained for several hours (provided your connective tissues have the necessary resilience, and you can avoid running out of glucose).  At this pace, the rate at which lactate is cleared from the blood matches the rate at which it is produced.  Typically this is at a lactate level of 2 mMol.  Roughly speaking, this is marathon pace.   Because blood acidity is a major influence on the urge to breathe, it also corresponds approximately to the point at which breathing becomes a noticeable effort.  Because I link my breathing rate to my step rate, I become aware that I have crossed this ‘aerobic’ threshold when I find I am more comfortable taking one breath every 4 steps rather than one breath every 6 steps. This ‘aerobic’ threshold is what Hadd refers to as the lactate threshold.

The second threshold is the pace beyond which lactate builds up to an intolerable level on a time scale measured in minutes.    I know I have crossed this ‘anaerobic’ threshold when breath rate increases to one breath every two steps – but I avoid this except in the final few hundred metres of a race (or occasionally on steep hills).     Races from 5K to HM are run at a pace somewhere between the aerobic and anaerobic thresholds, while the marathon is run at aerobic threshold.  So for the endurance runner, the success of the base building phase can best be quantified by measuring the pace at aerobic threshold, or as Hadd described it, the pace at lactate threshold.

Capillaries and VEGF

To re-iterate the key point, the late threshold is the point at which the rate of removal of lactate balances the rate of generation of lactate.   Therefore, a major goal of base-building is reducing the rate of generation of lactate.  Since no lactate is produced when fuel is metabolised in the presence of sufficient oxygen, the first requirement is delivery of a copious supply of oxygen to the muscle.  This requires enhancement of cardiac output and the development of capillaries in the muscle.  Both of these developments will be enhanced by running at a pace that is adequate to place the heart and muscles under some stress, but not too much.  The production of various growth factors, such as Vascular Endothelial Growth Factor (VEGF) that is responsible for stimulating the development of new capillaries, is promoted by a shortage of oxygen, so a degree of oxygen deprivation is required to maximise the development of capillaries.   The first major challenge is determining just where this ‘goldilocks’ level of stress occurs.    The answer is still a  matter of controversy, but before attempting to answer it, we need to consider several more issues.

Oxidative enzymes in mitochondria

Maximising power output at lactate threshold also requires the development of the oxidative enzymes in mitochondria that carry out the process of burning fats or glucose, and transferring the energy released to the high energy molecule, ATP, that is the direct source of energy for muscle contraction.   The required development of oxidative enzymes will occur if the system is appropriately challenged.  Running in the aerobic zone stimulates the development of oxidative enzymes, but it is also of interest to note that High Intensity Interval Training (HIIT) also leads to increased production of mitochondrial oxidative enzymes.

Removing lactate

In order to minimise accumulation of lactate when running near the threshold, we also need to maximise the ability to remove lactate.  This is done by a process that converts lactate back to glucose in the liver.  The process of transporting lactate to the liver, conversion to glucose and then transporting it back to muscle where it can be used again as fuel, is known as the Cori cycle.  It is likely that training at a pace that generates at least a moderate level of lactate will promote development of the enzymes of the Cori cycle.   However, the Cori cycle is not a source of ‘cost-free’ energy for muscle because conversion of lactate to glucose in the liver consumes energy.  Therefore, while it is beneficial to develop the enzymes of the Cori cycle, it is far more effective to minimise the production of lactate in the first place.

So far, the various issues we have considered emphasize the importance of training at a sufficiently high intensity to produce adequate stress on the system to stimulate production of growth factors such as VEGF; enzymes such as the mitochondrial oxidative enzymes and to a lesser extent, the Cori cycle enzymes.

The recruitment of different types of muscle fibre

However, this is only one side of the equation that must be balanced.  Muscles contain slow twitch and fast twitch fibres. The slow twitch fibres are specialised to function aerobically for long periods at low intensity. The fast twitch fibres are designed to generate high power output for a relatively brief time.  The fast twitch fibres occur in two types: aerobic and anaerobic.  The anaerobic are capable of generating the power needed for explosive movement.  They can develop power on a time scale that is rapid compared with the delivery of oxygen to tissues.  For this purpose, fuel efficiency is usually less important that speed of contraction.  These fibres generate their ATP via the rapid but uneconomical conversion of glucose to lactic acid.   Thus, when the anaerobic fast twitch fibres are engaged, acidity develops rapidly.

However, the nervous system is canny in the way it recruits muscle fibres.  As the requirement for increased power output increases, fibres are recruited in the order: slow twitch, aerobic fast twitch and finally anaerobic fast twitch.  At low power, slow twitch fibres are recruited and little acidity is generated.  Training at an intensity that puts a little bit of pressure on the slow twitch fibres will lead to further development of capillaries and mitochondria, thereby providing an increase in the power output that can be generated by these fibres.

If at the other extreme, you demand that your muscles generate a high power output, the anaerobic fast twitch fibres are recruited and the muscle is flooded with lactic acid.  Acidity makes muscle contraction less efficient and ultimately, the muscles shut down. It appears that the slow twitch fibres shut down first, although do not know of direct evidence for this,.  Whether or not the slow twitch fibres shut down first, when you run at a pace that preferentially recruits the anaerobic fast twitch fibres there is little opportunity for the prolonged activity that promotes the development of mitochondrial enzymes in slow twitch fibres.

Two options for increasing oxidative capacity

An unresolved  issue of major practical importance is what happens if you do multiple brief bursts of high intensity activity, separated by recovery periods in which lactate is cleared, as in high intensity interval training.  As mentioned previously, measurement of mitochondrial oxidative enzymes before and after HIIT reveals an increase in  oxidative capacity.  The question of whether this occurs preferentially in aerobic fast twitch fibres or occurs also in slow twitch fibres is not clearly established.  Nonetheless, if you want to increase oxidative capacity, you have two options: run slowly, though the gains are likely to be most rapid near to the point where appreciable recruitment of fast twitch fibres begins; or do high intensity interval training in which the recovery intervals are sufficient to clear lactate between the effort epochs.

Developing fat utilization

However, we should not focus only on developing the capacity to metabolise glucose.  At least in longer races such as the marathon, it is essential to derive a substantial proportion of the required energy from fat, simply because the glucose supply is inadequate.   The amount of energy that can be derived from fat increases up to a certain power output, but then decreases rapidly to near zero.  The power output at which the maximum rate of fat utilization is achieved varies between individuals, though on average, in trained athletes it occurs at around 63% of VO2max.  However, the level at which maximum fat utilization occurs can  be increased by appropriate training (and perhaps also by diet).  A marathon runner will be limited to an average pace that is not much greater than the pace at which maximum fat utilization occurs.  Therefore, in preparation for a marathon, increasing the proportion of VO2max at which fat utilization is maximal, is crucial.

Although several key questions remain unanswered, the above considerations provide a basis for rational planning of base-building.  In my next post I will address the question of the optimum practical strategy.

Is prolonged vigorous training bad for your health?

In a comment on my recent post, Steve asked what I thought of James O’Keefe’s recent TED lecture ‘Run for Your Life! At a comfortable pace, and not too far’.  The short response is that I agree with O’Keefe’s conclusion that if your goal is to maximise the length of your life, the best strategy is probably to exercise regularly at moderate intensity.  I also agree with a few of the specific points that O’Keefe makes, though I would not advance them in such a self-assured manner, because much of the evidence is incomplete.  In fact I found his manner of presentation more fitting for a snake oil merchant than a scientist.   He has presented a somewhat less dramatised version of the evidence in an article in the reputable Mayo Clinic Proceedings, though even that article contains at least one misleading inaccuracy.

There are several important respects in which his claims are misleading or simply wrong.   Other bloggers (for example Michael Accad, Lawrence Creswell and Alex Hutchinson) have posted thoughtful articles that subject his arguments to evidence-based scrutiny.   My purpose in this post is not point out the inadequacies of O’Keefe’s arguments, but rather to put forward my own thoughts of the evidence suggesting that training above a certain volume and/or intensity might be harmful.

The first crucial point that must be made is that the evidence on mortality shows that the more your train and the more vigorously you train, the greater your life expectancy, though the data does suggest that there are diminishing returns from a very large amount of vigorous training. The data present by Wen and colleagues in their article in the Lancet based on longitudinal data from 400,000 individuals, show first of all that people who exercise vigorously have a greater reduction in mortality rate than those who exercise moderately.  However, among those who exercise vigorously, the rate of reduction in mortality risk with increasing minutes per day spent exercising begins to flatten beyond 50 minutes per day.  However contrary to the message given by O’Keefe in his TED lecture, and also contrary to what O’Keefe states in his article in the Mayo Clinic Proceedings, Wen’s data does not show that the benefit peaks at 50-60 minutes per day.  In fact Wen made it very clear in a response to a question by O’Keefe published in the Lancet in March 2012 that the available data reveal that the mortality was even lower among those exercising vigorously for 120 minutes per day, but of course the numbers of individuals exercising vigorously for 120 minutes per day is small.  Wen quite sensibly refrained from extending the mortality graph beyond 60 minutes per day in his original article simply because the data is less reliable when based on a small number of individuals.

O’Keefe’s misrepresentation of Wen’s data in the TED talk, despite the fact that Wen had explicitly informed O’Keefe of the true situation about 8 months before the TED talk, is perhaps the most serious reason to distrust O’Keefe.  However, just because O’Keefe appears to be untrustworthy does not mean that all his conclusions are wrong.

So what does the data really show us?

In my opinion, the following conclusions can be drawn with moderate confidence:

1)      Exercise is associated with increased life expectancy, and at least up to 50-60 minutes of vigorous exercise per day, the more exercise you do, the lower the mortality rate.  The limited available data indicates that those exercising vigorously for 120 min per day have an even lower mortality rate, but the numbers are too small to allow confident conclusions.

2)      Prolonged vigorous exercise does produce changes in the heart, including an increase in the diameter of the ventricles and thickness of the ventricular walls.  I reviewed this evidence in detail in my post on Micah True.

3)      The increases in ventricular diameter and thickness are probably adaptive, in the sense that they make it possible for the heart to pump a larger volume of blood more forcefully to meet the requirement of a massive increase in cardiac output when running.  In athletes, unlike in individuals with overt heart disease, hypertrophy is usually accompanied by a potentially healthy increase in capillary density.  However, in at least some individuals, the remodelling of the heart is associated with disruption of cardiac rhythm.  In particular, there is strong evidence that prolonged endurance training increases the risk of atrial fibrillation (as reviewed in my post in June 2010 and several subsequent posts).  In those posts I also reviewed the evidence for increase in other rhythm disturbances, including potentially more dangerous disturbances arising in the ventricles

4)      Rhythm disturbances such as atrial fibrillation increase the risk of stroke, at least in non-athletes.   The question of whether atrial fibrillation produces an appreciable increase in the risk of stroke in athletes remains unanswered, though there are documented individual cases of adverse outcomes.  For example, in a 9 year follow-up study of 30 athletes with atrial fibrillation, Hoogsteen and colleagues found that 3 (10%) had died; 15 (50%) exhibited continuing paroxysmal atrial fibrillation; permanent atrial fibrillation emerged in 5 (17%) ; and 7 (23%) of showed no further atrial fibrillation.  Of the three deaths during the follow-up period, one was a sudden death during a race and is likely to have been due to a heart rhythm disturbance.  The other two were attributed to strokes.  Although Hoogsteen re-assuringly concludes that these deaths were not directly attributable to atrial fibrillation, the outcome is disconcerting.

5)       In at least some cases, especially males who have run many marathons over a period of many years, there is evidence of increased calcification of the coronary arteries, potentially predisposing to heart attack (reviewed in my post of Jan 2012).

How should we react to this rather confusing mass of evidence?    If your goal is simply to live a long and healthy life, the simple answer is to exercise frequently at a moderate intensity.  This will produce a substantial increase in your life expectancy with little risk of adverse consequences.  However, if you enjoy running, and in particular enjoy the thrill of running fast or the challenge of racing, the situation is different.  From a statistical point of view, if you train vigorously for an hour a day, your life expectancy will be much greater than if you spent that time watching TV and perhaps greater even than the life expectancy of a the health-conscious runner who runs only at moderate intensity, but the data warrants more detailed inspection.

It is encouraging that the data from Wen’s study showed lower mortality risk for the small number of individuals exercising vigorously for 120 minutes per day.  It is tempting to conclude that the additional health benefits from such training might outweigh the increased risk of adverse effects such as cardiac rhythm disturbances. However, we should hesitate before concluding that 120 minute per day of vigorous training causes the observed reduction in mortality.  Once we are dealing with a small number of exceptional individuals, it is necessary to be very cautious in assuming the direction of the cause that generates the statistical correlation.  It might be that only individuals with an extraordinarily robust natural constitution can sustain this level of training.  Whatever we might conclude regarding overall mortality associated with extensive vigorous training, the inescapable conclusion is that there is a real risk of serious adverse cardiac events in a minority of individuals.

The crucial question

If we wish to continue to train extensively and vigorously, the crucial question is ‘can we do anything to ensure that we are not in the minority who suffer a serious adverse event?’  Unfortunately, the evidence is not good enough to allow absolute assurance of safety.  However I think there is a growing body of evidence that helps us to avoid the circumstances that are most risky, and as a second line of defence, there are ways in which we might identify the onset of potentially serious disturbances and deal with them before they become dangerous.

First of all, what do we know about the circumstances that increase risk?  For about 24-48 hours after a marathon, blood levels of troponin, which is a marker of trauma to heart muscle fibres, are elevated, and the strength of ventricular contraction is weaker.  Almost certainly the heart is more vulnerable during this period.  However, the evidence also suggests that these signs of trauma are transient.  The heart recovers.  If it is true that that the benefits of training reflect repair of transient trauma, the heart might be even stronger afterwards.  So there is a very sensible way of increasing the odds in ones favour: make sure that you allow adequate recovery after a strenuous event such as a marathon.  My own belief is that full recovery from a marathon raced to the limits of one’s ability, takes a period of several months.

Chris Mcdougall, who made Micah True the central figure in his book ‘Born to Run’, reports that True had done a six hour run in the Gila desert the day before he died.  Anecdotal evidence suggests that True had not taken his dog with him on the fateful last run because the dog’s paws were sore from the previous day’s run.   If indeed McDougal’s report is correct, I think that a plausible explanation of why True died during a mere 12 mile run is that he had not recovered adequately from a strenuous run the previous day; a run that might well have been expected to have produced transient damage to his heart.  This is of course mere speculation based on anecdote.  Other theories such as the possibility that he suffered from Chagas disease, which is endemic in New Mexico, must also be considered.  But the point that I wish to illustrate is that if you enjoy running marathons or more extreme endurance running, you are not a hapless pawn at the mercy of statistical prediction.  You can alter the odds and you are less likely to be among the minority with serious adverse outcome if you are well attuned to the need for adequate recovery.

Chronic inflammation

As Dr O’Keefe emphasized in his TED talk, the likely mechanism by which extensive vigorous training might damage the heart is chronic inflammation.  So perhaps the most important thing to seek is a way of identifying the development of chronic inflammation at an early stage, and alleviating it.  Our current understanding of chronic inflammation remains inadequate, but there is a growing body of useful information.

Chronic inflammation is also likely to be the mechanism responsible for the over-training syndrome, discussed in my post in March 2010.   There are some promising strategies for identifying both the early stage of over-reaching, manifest as sympathetic over-activity, and the more enigmatic late stage of over-training characterised by parasympathetic over-activity.    Although the tests for over-training are still rudimentary, the availability of heart rate monitors that record the variability in intervals between heart beats (R-R variability) has opened the door to the possibility of early identification of the excessive parasympathetic activity characteristic of over-training.   However the reliability of current procedures has yet to be established adequately.  Alternatively, measurements of heart rate during exercise, such as the Lamberts and Lambert sub-maximal cycle test, are showing promise.

If over-reaching is identified in the early stage, it can be alleviated by scheduling a day or two of recovery.  The more advanced stages of over-training are much more difficult to deal with, though it is encouraging that studies of animals indicate that even quite severe chronic inflammation can resolve during a sustained period of lighter exercise.

Not only are there sound principles regarding recovery from strenuous events together with a growing body of information about early identification and alleviation of over-training, but, as a second line of defence, a heart rate monitor with the capacity to record R-R intervals might also provide advance warning of transient minor rhythm disturbances occuring long before a dramatic serious disturbance.  Unfortunately, here we get into sparsely charted waters where there is little good evidence to guide us.  Furthermore, there is a danger that artefacts arising from poor electrode contact or other interference can confound the interpretation of erratic R-R recordings.

My experience

I still remain uncertain about the cause of the erratic rhythms I had recorded in 2009 and 2010.  I am now confident that many of the oddities were due to poor electrode contact, but I am inclined to think that others, especially the sharp spikes followed by a partially compensatory pause, were likely to be premature atrial contractions.  In an elderly person, premature atrial contractions are not uncommon, but nonetheless might be a warning sign.  I was intrigued to note that on one occasion when I had become seriously dehydrated after being forced to make an unexpected long detour during a run through parched desert terrain, that the frequency of the sharp spikes was increased.  Maybe they were artefacts due to poor contact between the electrodes and my dry skin, but nonetheless I took that experience as a warning to avoid serious dehydration in future.

I am re-assured by the fact that in the past year, during which I have followed a markedly periodized training program that has nonetheless included a greater volume of training than in any recent year and produced better race performances, I have observed fewer sharp spikes in the R-R records.  While the interpretation of odd rhythms when they occur is fraught with ambiguity, the current rarity of spikes is re-assuring.  Perhaps it is a consequence of more careful planning of my training.  While my own anecdotal experiences prove very little, I think that they do provide grounds for further investigation of the potential value of a heart rate monitor with R-R recording capability as a screening tool to detect circumstances where vulnerability might be increased, or to identify oddities requiring further investigation.

In my younger days, I was a keen mountaineer.  A few months ago when in Switzerland to give a talk, I took the opportunity to spend a few days in the mountains, and was reminded of how awe-inspiring it is to climb amid snow covered peaks.  The sense of awe is all the greater when the crisp breeze chills your face and there are few sounds others than the chatter of your companions and the calls of the choughs circling in the air below you.   Viewing the mountains through the glass window of an overheated restaurant surrounded by slushy snow at the top of a cable car ride offers a pale and soggy comparison.  Mountaineering is intrinsically dangerous.  The overt dangers are probably greater than those from the most extreme endurance events.   Some of the risks are inherently unpredictable, but nonetheless, thorough knowledge, good planning, sound judgement and a small amount of highly technical equipment can do much to reduce the risks.

The comparison with running is imperfect, but the delight in executing a finely balanced move on delicate holds across a rock face, the grandeur of the summit views, and the satisfaction in knowing that you have pushed yourself to the limits of your physical and mental strength are a counterpart to the delight of running with graceful style along woodland trails and the satisfaction of racing to the limit of your physical and mental strength.  I am therefore happy to embrace the risks that are involved, but nonetheless, just as I regard equipping myself with knowledge, expertise and equipment to maximise safety is part of the satisfaction of climbing, I consider that the challenge of learning how to minimise the risks is a part of the satisfaction of running well.

Hopping: Paula Radcliffe, Mo Farah and me

On Saturday, I repeated the hopping test. I consider the distance covered in 5 hops on one leg is a good test of running-specific strength.  Seb Coe used to do a similar test.  He could cover 25 metres on 8 hops, but as a cronky old-timer my target is much more modest.  Before the episode of arthritis that afflicted me in January 2010, I could cover 9.71 m in five hops on the left leg and 9.24 m on the right.  The discrepancy between legs reflected the fact that previous episodes of arthritis had affected my right knee more than my left.  In contrast, the episode in early 2010 attacked my left knee (in addition to my left wrist and neck).  The arthritic pain lingered through most of 2010, causing me to minimise forces transmitted through the knee.  By December 2010,  I had lost about 20% of my hoping strength, and now my left leg was weaker than my right; I achieved 7.39 m on the left and 7.44 on the right.  My attempts to remedy this loss by plyometrics in early 2011 were thwarted by recurrence of pain in the left knee.

Several other health problems also interfered with training but by late summer 2011, I was once again able to train regularly.  As described in recent posts, in the following 11 months I trained regularly, unhindered by illness or injury, and my aerobic fitness improved greatly.  But by July 2012, I was stuck in a rut.  I found it very difficult to maintain a pace of 5 min/Km for more than a few Km despite evidence of good aerobic fitness.  It appeared that I had such small reserves of muscle strength that even at 5 min/mile pace I was recruiting not only all my type 1 fibres but also most of my type 2 fibres.  Not surprisingly, I could not maintain such a pace for more than a few Km.  A repetition of the hopping test in July confirmed that lack of muscle power was the problem. I covered 7.45 m on the left and 7.77 m on the right.  Eleven months of mainly aerobic training, with a modest amount of hill work and interval training, had produced only a 2% improvement in hopping.

At that stage, I commenced a ‘quick and dirty’ program of weight lifting – ‘dirty’ in the sense that I built up the load quickly, rather than painstakingly developing by the technique and basic all round strength necessary for safe lifting at near maximal capacity.   But at that stage, there would be no prospect of going to maximum loading before the RH half marathon in September so I spent a few weeks building rapidly to moderate loads before returning to predominantly aerobic training for the final few weeks.   In the event, the strategy worked. I ran a reasonably good half-marathon, and then a few weeks later, a satisfying 5K.

Because maximal-effort hopping presents significant risk of musculo-skeletal injury for an elderly person, I perform the test sparingly.  Nonetheless, by last Saturday it was time to repeat it, both to confirm that my training since July had indeed produced an increase in hopping performance, and to provide a base-line for assessing future improvement.   I achieved 8.65 m on the left and 8.46m on the right.  Thus in the past 3 months, I had improved a further 8% , and have now recovered about half of the strength that I had lost following the arthritis in 2010.   In contrast to the 2% improvement produced by 11 months aerobic training including some hills and intervals, 3 months that included a mixture of weights, drills and further aerobic training produced an 8% improvement.   This evidence of increased hopping distance accompanying the improved running performance provided addtional confirmation of the conclusion that I was stuck in a rut in July on account of inadequate muscle power to utilise my aerobic capacity.  The fact that my hopping performance is now about halfway back to where it was at the beginning of 2010 indicates that there is scope for further improvement in hopping capacity, and hopefully, also in running speed. Nonetheless, the question of whether weight training is useful for distance runners remains a matter of controversy

What do the Kenyans do?

In a balanced review of the issues, Pete Pfitzinger remarks with a touch of irony ‘the Kenyans are so secretive in their iron-pumping that no one has ever seen them lift. Travel to Ethiopia, and you will see an equally impressive absence of muscle-building.’  This observation is indeed reason to consider the issues carefully before embarking on a time consuming and demanding weight lifting program.  However, Pfitzinger’s observation must be set against the evidence that very demanding resistance training is not unknown in Kenya.  The fascinating video of the BOSS Baltic team including Asbel Kiprop (1500m gold medallist in Beijing and world champion in 2011) training in the rain at Iten stadium in November 2011 reveals an extremely demanding session that included dragging car tyres around a water-logged track; running against a restraining waist band; and intense plyometric jumps over a series of hurdles.

The experiment with N=1

While there is abundant scientific evidence that combining weight lifting with aerobic training improves running-specific factors such as running efficiency and time to exhaustion when running in the upper aerobic zone, there is no large study that has demonstrated that weight training improves racing performance at any distance from 5K to marathon.  However each athlete is an individual and must weigh up the evidence of what is likely to be helpful for him or her.  There is an abundance of anecdotal evidence regarding the benefits of weight training for individual runners.  How closely do the anecdotes match my own situation?

Paula Radcliffe

Her fourth place in the 10,000m final in Sydney in 2000 demonstrated yet again that Paula lacked the strength in the final lap required for victory at the highest level of competition.   In an attempt to define the problem, Irish physiotherapist, Gerard Hartmann asked Paula to do 20 hops up and down from a 16 inch high box as fast as she could. In contrast to Kelly Holmes who had 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, Belgium) and also won her debut marathon in London, in a time only 8 seconds slower than Catherine Ndereba’s world record of 2:18:47.  Later that year, in Chicago, she staked her claim to ownership of the world record by slicing 89 seconds off Nderaba’s best.  The following year, in London in April she recorded the awe-inspiring time 2:15:25, a mark that remains unchallenged.

In my post six months ago following Mary Kietany’s victory in the London marathon in April, in which she shaved a few seconds of Katherine Ndereba’s best, I speculated that a new generation of Kenyan women might be about to mount a serious challenge to Paula’s record.  I should also have added Ethiopian woman to the field of contenders as Tiki Gelana had recorded 2:18:58 in Rotterdam a week before Kietany’s win in London, and Aselfach Mergia had broken the 2:20 mark earlier in the year in Dubai.  Indeed there was no reason to limit my horizon to Africa as the second fastest female marathon runner of all time is Liliaya Shobukove of Russia with a time of 2:18:20 in Chicago in 2011, while about a dozen other woman including Mizuki Noguchi, Irina Mitenko and Deena Kastor have recorded times under the 2:20 mark.   However, so far there has been no sign pointing to an imminent quantum leap in women’s marathoning.  Since April, the only woman to get anywhere near 2:20 was Aberu Kebede with her winning time of 2:20:30 in Berlin in September.  Paula’s record from 2003 looks as secure as ever.

As I watched the video of the BOSS team training in the rain soaked stadium in Iten, I was struck by the contrast between the male athletes and the lone female athlete wearing a red top and blue trousers.  She too dragged the tyre around the track, and battled persistently against a restraining band tethered to a post, but the power of her legs paled in comparison with that of the men.  I do not know what distances she races, and wish to draw no conclusion other than noting that the video provided a graphic illustration of the major gender difference in strength, a difference that is manifest in the power of the movements that are required for running.  In my post in April I had speculated that women should less severely disadvantaged relative to men in the marathon than in shorter events because the event is largely fuelled by reserves of fat, but I think that speculation missed a crucial point. Even the marathon is an event requiring strength, a point illustrated not only by Sammy Wanjiru in Beijing but even more dramatically by Wilson Kipsang Kiprotich in London in April of this year.  His powerful surge shortly after the halfway mark crushed most of his opponents.  He tried a similar tactic in London in August.  But whether it was merely the heat of that August day or the fact that his body was beginning to fatigue after three top-level marathons within 10 months (starting with his near world record breaking win in Frankfurt in October 2011), his strength failed him in August and he faded to third place behind Stephen Kiprotich and Abel Kirui.    Nonetheless, it is clear that the men’s marathon is a test of strength as well as aerobic capacity.   I suspect that Paula stands unrivalled among female marathoners not only on account of her tremendous aerobic capacity but also on account of the strength program that Gerard Hartmann designed for her in light of her dismal hopping test performance in 2000.

However Paula’s story has a sad coda.  After dropping out of the marathon in Athens in 2004 apparently due to complications arising from treatment for a leg injury; her subsequent game but ill-starred attempt in Beijing in 2008 following a stress fracture; and then a failure to even get to the starting line in London in 2012, her Olympic dreams have been dashed.  Of course luck plays a role.  But the video of her world record breaking run in Chicago in 2002, and of her spectacular run in London the following year, reveal a runner tensing almost every muscle as she strains to drive herself onward. Perhaps the unwarranted muscle tension provides a clue to the contrast between her unrivalled performances when her body lasted the distance, and the numerous occasions when her body failed her.   I understand that Gerard Hartmann made a determined efforts to help her reduce the head bobbing that characterised her running prior to 2002, but I wonder whether she might have added an Olympic medal to her otherwise unrivalled record if she had devoted more attention to integrating her strength into a well coordinated, relaxed running style.

Mo Farah

In a press conference shortly after Mo Farah’s dominant performances in the 5000m and 10000m in London in August, Alberto Salazar described how, when Mo joined him team in Oregon 18 months earlier, he was a skinny distance runner who performed strength exercises like a 90 lb weakling.  He recognised that if Mo was to fulfil his potential and hold off the world’s best in the final lap of a 5000m race, he would need strength.  Salazar got him lifting weights alongside Galen Rupp, and the transformation of his physique was dramatic.  In Alberto’s opinion, the seven hours every fortnight spent lifting weights in the gym played a more important part in Mo’s victories in London than the 110 miles a week of aerobic training.

Thus,  anecdotal evidence regarding both Paula Radcliffe and Mo Farah indicates that in individuals in who have an identifiable deficit in strength, resistance training including the lifting of heavy weights can produce worthwhile improvements in running performance.

My plans

My goal is to run a good marathon at age 70 but the first step is to run a half-marathon in less than 100 minutes.  I am now within sight of that goal, but I think the evidence that I am limited more by lack of muscle power than by my aerobic fitness in now unequivocal.  There are several options: I could build type 2a fibres by running long hills; I could increase my strength and endurance by training in a weighted vest, just as I acquired the power required to run a marathon in under 2:30 over forty years ago by spending many days walking and climbing up mountains with a pack weighing between 30 and 40% of my bodyweight on my back; or I could lift weights.  I think that in old age, as anabolic hormone production wanes, the surge of anabolic hormones produced by brief periods of heavy lifting makes weight lifting the preferred option.

Lifting weights will develop type 2a aerobic fast twitch fibres.  While these fibres are in themselves of considerable value when running near the upper end of the aerobic zone, especially on a hilly course, the major requirement for a marathoner or half marathoner, is abundant type 1 fibres.  Gehlert’s study of cyclists who switched to program of high volume/low intensity training demonstrates that type 2a fibres can be transformed to type 1 fibres, at least in those individuals who have a predominance of type 2a fibres prior to the switch in training.  Unfortunately, the role of other factors such as one’s genetically determined predisposition towards type fibre 1 dominance in promoting or inhibiting this transformation remain a matter for speculation.

Whatever plans I make for training, it will be a unique experiment on myself.  Neither anecdotal accounts of the experiences of others such as Paula Radcliffe and Mo Farah, nor systematic studies of groups such as that conducted by Gehlert will answer the question of how I can best develop the muscle strength that I require.  However, the evidence suggests that the best strategy should include three phases: strength development; incorporation of this strength into a well coordinated relaxed running style: and finally the transformation of at least some of the type 2a fibres to type 1 fibres while I rebuild my aerobic capacity.

As outlined in a recent response to a query from Robert, my current provisional plan is as follows:

Phase 1 (8 weeks) : primary goal – strength development. The key activity will be high load, low repetition weight lifting, together with hills and drills to initiate the incorporation the additional strength into running-specific action, and a modest amount of low aerobic training to maintain my current type 1 fibres.  I anticipate increase in volume of type 2 fibres with only small loss of type 1.

Phase 2 (3-4 weeks): primary goal – incorporation of strength into running action.  I will do hills, drills and intervals to maximize incorporation of strength into a relaxed, efficient running action, with a small amount of weight lifting to maintain strength and a modest amount of low aerobic training. I will evaluate progress in a 5K time trial in January.  The anticipated main changes in muscle will be refined recruitment of fibres rather than a change in fibre composition.

Phase 3 (12 weeks): Primary goal – aerobic development.  I will do predominantly aerobic training with increase in length of runs; some weight lifting to maintain strength; drills. hills and intervals to maintain speed. The program will end with a two week taper to a half marathon in April.   I anticipate conversion of type 2a to type 1 fibres in this phase, but also hope to maintain a moderate proportion of type 2a fibres.

Ewen has picked up the gauntlet in a challenge to be the first to break100 minutes for a half-marathon in April.  My eyes remain focussed on the marathon in the long term, but in the short term, this virtual duel with a fellow spirit from the other side of the globe will add a little spice to my endeavours.

..

Resistance training for distance runners

Classically, a sprinter has the torso of an ox while a marathon runner has spindly legs and arms.  Sprinters spend a substantial time in the gym lifting weights and afterwards eat a lot of protein; marathon runners spend even longer on the road depleting their muscle glycogen and then consume carbohydrate to replace it.   When finishing a long run at a pace near to race pace, marathon runners are actually in danger of burning the protein from their own muscles.  If they work with weights it is usually using high repetitions at moderate load to build up strength endurance rather than the power which a sprinter aims to develop with fewer repetitions with much heavier weights. These distinct training patterns have proven successful, on the one hand for many sprinters and on the other hand for many endurance runners.   Clearly, the physiological needs of the sprinter, whose first requirements are muscle power and neuromuscular coordination, differ from those of the endurance runner, whose primary need is to supply oxygen and fuel to the muscles at a rate adequate to sustain aerobic metabolism for long periods.

However, it is interesting to note that sprinting speed is a good predictor of one’s ultimate performance in distance events.  Nonetheless, a novice endurance runner will get best value from time spent training by working on building aerobic capacity.  A powerful engine is of little use without oxygen and fuel.  But once oxygen and fuel supply are more than adequate, perhaps it is time to focus more on muscle power.

There is an even more general rule about training and that is: repeating the same training stimulus time and time again yields diminishing returns.  When the returns begin to diminish it is worth asking the question: what is now limiting my performance and what training stimulus might best break through the current limit?

Limitations

In recent years several illnesses and also lack of time for training had been the most easily identified limitations, but the past year has been different.  I been free of illness and injury, and have actually spent more time training than during any year of my life – even those years over four decades ago when I could run a marathon in less than two and a half hours, though it should be noted that in those days, other activities especially mountaineering, contributed a great deal to my basic fitness.

In the past year the time spent training has produced substantial gains.  However, about three months ago, in the final few months of preparation for the Robin Hood Half Marathon at the end of September, it was clear that I had run up against a serious limitation.  My aerobic fitness, as indicated by low heart rate when running at an easy pace, was good.   My customary measure of aerobic fitness, the number of heart beats per Km, was typically in the range 630-640 b/Km during low aerobic runs, and there was very little upward drift of heart rate during long runs.    I would have anticipated that such a level of aerobic fitness would allow me to maintain a pace in the range 4:35-4:45 min/Km for the duration of a half marathon, to produce a finishing time of 1:40 or less.   But to my dismay, when I tried to maintain paces in this range, even for a few Km, I simply couldn’t muster the speed.  I could not even maintain 5 min/Km pace for 4 Km.   So it appeared that my limitation at that time was not aerobic fitness.

It was easy to identify the problem: the first factor is that I am in my late sixties, and suffering the general loss of muscle strength that accelerates alarmingly in the later part of the seventh decade.  The second problem was that I had suffered an episode of acute arthritis two years ago that had affected several joints including my left knee.   Painful movement leads to involuntary decrease in application of force, and as a result, my leg muscles, especially quads and hams, had atrophied even more than would be expected due to aging.  The hopping test, in which I measure the total distance covered in 5 consecutive hops on one leg, had deteriorated dramatically from around 9.5 metres to 7.5 metres.  In the subsequent two years lingering pain in the knee thwarted my attempts to introduce a program of plyometrics, while, ironically, marked pain in my arthritic left wrist made it difficult to lift weights.   It was clear that I had to find some way around these problems.

Fortunately, around the time I received an email out of the blue from a runner named Kieren. Several years ago Kieren’s blog had inspired me both to run and to blog, and I had been saddened when he suffered an injury, stopped running, and eventually stopped blogging.  I had discovered incidentally that he still posted occasionally on the Fetcheveryone website, and I had been interested to see that he had taken up resistance training a few months ago.    Although his recent email to me was triggered by my posts on heart rhythm, we got to discussing resistance training. He emphasized the value of squats for building ‘whole body’ strength, but especially for strengthening the major muscles of the posterior chain: the glutes, hams and hip adductors.  He recommended an excellent book by Mark Rippetoe which provided detailed clear guidance on how to squat safely and effectively.

As I mentioned in a previous post, at that stage I commenced a gradual progressive build up of weights and after four weeks was delighted by two outcomes: my painful arthritic wrist was much less painful, presumably due to increased support by stronger forearm muscles, and my pace during stride-outs at around 80% maximum effort, had increased, though of course, this is a rather imprecise measure of improvement.  Nonetheless, the signs were encouraging.  But by that point in my preparation for the Robin Hood half marathon, it was necessary to revert to predominantly aerobic training.  However, I continued with body weight exercises and drills.  Although there was not time to properly assess my ability to sustain a higher speed in those final few weeks before the race, short tempo runs during the taper suggested that I was now able to  maintain a pace of 5 min/Km or even a little faster with reserve power.  In the event, this proved to be the case. I crossed the line in 1:41:50, reflecting an average pace of 4:50/Km for the full 21.1 Km.  Some of this improvement was no doubt due to a successful taper, but on balance, the prospects for further improvement with continuation of strength development looked promising.

Body weight

But before committing myself to a major program of resistance training, it is necessary to consider the crucial issue of possible weight gain.  For the sprinter, the greatest energy cost of running is the cost of re-positioning the swinging leg.  But at the paces typical of endurance running, the greatest cost is the cost of elevating the body on each stride, and this cost is directly proportional to body weight.    Irwin Stillman estimates that a long distance runner should weigh 15% less than the average non-athlete of the same height, though some coaches consider that 10% less than average is ideal.   Until one reaches the state of emaciation where hormonal and immune function begins to be compromised, loss of fat is almost certainly beneficial to the distance runner.   Weight training is potentially effective for promoting fat loss, and therefore, a substantial proportion of the weight change in early stages of a weight lifting program are likely to a beneficial loss of fat.  I am currently about 9% below average weight for my height, so I do not need to lose much more weight.  Some of this deficit is due to muscular atrophy, so I will probably profit from replacing fat by muscle.

But depending on the regimen adopted, gain in muscle mass from weight training might well overshadow the loss of fat, especially for a distance runner with little fat to spare.  So if my running performance is to improve, it is crucial that any gain in muscle mass ‘pays its way’ by producing an increase in power output that more than compensates for the extra work I will have to do in order to get airborne on each stride.   It will also be crucial to ensure that I maintain the ability to deliver enough oxygen and fuel to the muscles to sustain aerobic metabolism for several hours.

Muscle fibre types

This brings us to the key issue of types of muscle fibre.  The sprinter relies largely on type 2B fibres, anaerobic fibres dominated by massive contractile machinery capable of rapid, and hence powerful contraction.  Muscle contraction is produced by  the ratchet-like interaction of actin and myosin fibrils that slide past each other as a result of making and breaking molecular bonds, employing energy provided by the energy molecule, ATP.  Several different types of myosin fibrils exist.  Type 2B fibres contain ‘heavy duty’ myosin capable of very rapid contraction.  Thus, type 2B fibres are best equipped to utilise readily available ATP and creatine phosphate, which can be rapidly converted to ATP.  Although oxygen is subsequently required to replenish the supply of ATP and creatine phosphate, this is usually done at a leisurely rate during recovery.  Therefore, the development of type 2B fibres sacrifices capillary density for the sake of contractile machinery.  These type 2B fibres are of limited use to a distance runner.

The distance runner relies largely on type 1 fibres in which there is a balance between contractile machinery and capillary density, and it addition, abundant mitochondria. The mitochondria contain the oxidative enzymes required to generate ATP by oxidizing fuels such as glucose.  Thus type 1 fibres are well suited to aerobic metabolism.  However, the variant of myosin in type 1 fibres can only contract at about 1/10^th the rate of the variant found in type 2B fibres.  Therefore the type 1 fibres are best suited to producing a modest power output for long periods using aerobic metabolism.   But it is unlikely that lifting heavy weights will do much for the development of type 1 fibres.

The next question is: what fibres are enhanced by resistance training?  The answer is perhaps a little surprising.  Resistance training enhances mainly type 2A fibres.  These are the aerobic fast twitch fibres.  They contain a type of myosin fibril capable a fast contraction, but are also fairly well adapted to aerobic metabolism.  They contain substantial numbers of mitochondria and a moderately high capillary density.    Therefore, they are well equipped for tasks that require a moderately large power output sustained for a moderate duration, tasks such as running up long hills.   As almost all cross country events and many road races include some hills, it is clearly desirable for the distance runner to have fairly well developed type 2A fibres.  Unfortunately, I have poorly developed type 2A fibres.  In my duel with Emily the Keyworth Turkey Trot two years ago, I could not match her on the ascents and had to rely on shrinking the gap during the descents.  Similarly in a 5K parkrun two days ago, I was very evenly matched with a young man on the level stretches, but could not match him on the mild ascents, and again, had to rely on closing the gap during the descents.  So, it is likely that further development of type 2A  fibres will in itself improve my performance on hilly courses.  But the cardinal question is: is it possible to convert type 2A fibres into other types of fibre?  The answer to this question is still a subject of some uncertainly, but encouraging evidence is emerging

Conversion between fibre types

Before tackling the crucial question of the possibility of converting type 2A fibres to the type 1 fibres required by the distance runner, it is intriguing to ask how it is that weight training helps sprinters develop the type 2B fibres that are the key to speed.  Enigmatically, the answer appears to be: by doing very little.  It appears that type 2A  fibres naturally revert to type  2B fibres when not subjected to repeated loading.  It is probable that type 2B fibres are the default state to which other fibres regress if not required to work.  This is illustrated by the fact that after a period of paralysis, the proportion of type 2B fibres is high.   Thus, it is likely that the best strategy for a sprinter is marked periodization.  In the pre-season, he/she should lift heavy weights, leading to the development of type 2A fibres.  Then during the competitive season, the emphasis should be on sharpening neuromuscular coordination.  Meanwhile the type 2A fibres developed during the pre-season weight lifting will revert to the required type 2B fibres.

But can an endurance athlete convert the type 2A fibres to type 1 fibres?  The answer is less clear.  It appears to depend on the initial fibre composition of the muscle.  In a study of 21 cyclists who undertook training program in which volume of training was increased while intensity decreased, there was a significant decrease in proportion of type 2A fibres and a trend toward increased proportion of type 1 fibres, when averaged across the entire group.  However, perhaps the most important finding emerged when the 21 cyclists were subdivided into a group with high initial proportion of type 1 fibres (the HPS group) and those with a low initial proportion of type 1 fibres the LPS) group.  In the HPS group, the change to higher volume, low intensity training produced no appreciate change in fibre composition, whereas in the LPS group, there was a marked increase in type 1 fibres and a decrease in type 2A fibres.   The question of whether or not the difference in initial proportion of type 1 fibres was determined by genes or by previous training was not addressed.

Thus, the study demonstrates that an increase in training volume and reduction in intensity is likely to produce a shift from type 2A to type 1 fibres in some endurance athletes, but not in others, and that difference in training effect is determined by the proportion of type 1 fibres at the beginning of the high volume training.  Unfortunately, the question of whether it is the genetic influences on the initial fibre composition or previous training experience that determines the likely outcome remains unclear.  However, it seems to me that prior training is the mostly likely factor, since cyclists with a genetic predisposition to a preponderance of type 1 fibres would have been more likely to be in the HPS group at the start.

I suspect that due either to my genes or to my childhood experience of running to and from school, I have a natural preponderance of type 1 fibres, and therefore, in my present state, further high volume. low intensity training will not increase my proportion of type 1 fibres.  However, the available evidence indicates that a program of weight lifting might increase my proportion of type 2A fibres and subsequent high volume, low intensity training might lead to an increase in type 1 fibres.

The available evidence also indicates that the outcome of training depends on one’s initial state at the beginning of the training.  There is no single answer to the question of how best to train.  But after a careful evaluation of my own condition, I think that a program of weight training is a good bet in my case.  However it is also noteworthy that in order to achieve the distance runner’s theoretical ideal of a very low amounts a type 2B, moderate proportion of type 2A and a large proportion of type 1 fibres, I need to revert from weight training to aerobic training well in advance of my next half marathon.

There are additional issues to consider.   These include the effect of weight training on hormones, especially growth hormone, and also the question of what particular exercises I should include in my weight training program.  I will return to each of these questions in future posts.  I will finish this post with an account of how I plan to monitor progress.

Monitoring progress

I will monitor three ‘running specific’ variables: my time for a 5K, the distance achieved in 5 consecutive hops on one leg, and my weight.

With regard to 5K performance, I did my base-line test in a parkrun last Saturday.   I achieved a time of 22:19.  I was delighted with this, since in my first parkrun a year ago, run after about three months of systematic training, including both hills and intervals, I had achieved a time of 24:48.  Thus, in the subsequent year, I have managed to reduce that time by about two and a half minutes.   Whether this reduction can be attributed to the intervening aerobic training or to the resistance work and drills over the past few months in uncertain. The fact that I could not maintain 5 min/Km pace for 4 Km three months ago, at the end of a long period of predominantly aerobic training, suggests that it was a combination of both.   Thus, I am cautiously optimistic that an appropriately periodized combination of weights, drills and aerobic training will lead to yet further improvement, though of course, reduction from a starting point of 22:19 is a greater challenge than reduction from a starting point of 24:48.

An finally, as a counterbalance to the somewhat gruesome photos of my efforts to conjure speed from my atrophied leg muscles in the RH half marathon, here are some photos taken during the two-lap parkrun on Saturday, by the husband of Plodding Hippo, a runner and doctor whose wisdom on running-related medical matters is much valued by readers of the Fetcheveryone website.

Nearing the halfway point. Original at http://www.flickr.com/photos/nozzawales/8105220722/in/pool-2059413@N20/

About to begin the final sprint with about 100 m to run. Original at http://www.flickr.com/photos/nozzawales/8105262635/in/photostream

The end of the taper

It is two days from the end of my taper for the Robin Hood half-marathon on Sunday.  Tomorrow will be a rest day.  On Saturday I will run about 4 Km easily, including several short stride-outs at estimated race effort to dispel any of the sluggishness that can develop during rest days, and consolidate the neuromuscular coordination required for racing.

I am pleased with how my legs have responded to the taper.  In the final few weeks of training I had been disappointed by the fact that I found it difficult to achieve pace anywhere near a reasonable race pace during tempo runs.  I hoped that this was due at least in part to chronic tiredness of my leg muscles, so the main goals of the taper were to allow my legs to recover, while including enough running in the vicinity of race pace to develop the neuromuscular coordination required for racing.

The figure shows the profile of time spent in each of the training zones over the past three weeks.  Despite a 50%  reduction in training volume I have maintained a near constant proportion of around 25% of training time in the upper aerobic zone, throughout the taper    I have been pleased to discover that whereas two weeks ago a pace of 5 min/Km required an effort somewhat greater than I could imagine sustaining for the HM distance, today, I felt comfortable and fluent at pace of 4:50 /Km.   In part this is surely because my legs are less tried, but I think it is likely that incorporating some faster running, together with two sessions of Pete Magill’s drills, has helped re-awaken the muscle fibres required for racing.

So the taper has produced the intended improvement in fluency.  But what does this tell me about my prospect of maintaining that fluency and pace for the full distance? In several of the long runs during the previous 6 weeks I had planned to maintain a pace near HM race pace for the final few Km.  However, the fastest pace I had achieved in a long run was 5:14 /Km – a pace which would produce a time of  110 minutes for the HM.  The evidence from the short runs during the taper suggests that I can do substantially better than 110 minutes, but there is no way in which I can answer the  question of how my legs will cope with the full 21.1 Km distance, in advance of the race itself.

So planning a sensible pace for Sunday is still tricky.  If I start at around 4:50 pace, it is not clear how long I would be able to maintain that pace.  Commonsense dictates that if my goal is to maximise my chance of recording a ‘creditable’ time, I should start at around 5 min/Km pace or even a little slower, and hope that I can run a negative split to get me to the finish in around 104-105 minutes.   However, somewhere deeper in the intuitive recesses of my brain, where less tangible evidence based on my running history is weighed up alongside the numerical data recorded in recent training runs, I believe that I can run a time faster than 104 minutes.  Therefore, provided I feel comfortable after I have emerged from the initial melee of the massed start, I will abandon rationality and prudence, and let the intuitive recesses of my brain set the pace. I will trust that these intuitive reaches of the brain will weigh up the various non-conscious feed-back signals from my body together with subliminal memories from the past in way that allows me to extract the maximum performance that my body is capable of achieving.  In the end, it will be my body rather than the stop-watch that tells me whether or not I have run a well-judged race.

An unconventional start to the taper

As outlined in my recent post, I have been able to train consistently, and largely according to plan, for over a year. I have done virtually all the planned key sessions in preparation for the Robin Hood half marathon on 30^th September – the main problem is that my pace has been well below the target which I set in April.

The target was optimistic.  My 5Km performance a year ago indicated that my target HM pace should be around 115 minutes but I was sure I could do quite a lot better.  108 to 110 minutes might have been a sensible guess.  However, I decided to go with my dream and planned a training schedule aiming for 100 minutes.   The chance of achieving this wild dream depended on how well my aging legs could cope.  My muscles had atrophied not only with age but also as a result of a protracted bout of arthritis early in 2010.  During the Keyworth Turkey Trot HM in December of that year, my legs had let me down.  In the subsequent months I had to abandon my attempted program of plyometrics because of an exacerbation the arthritic pain.  However when I planned my preparation for this years’ Robin Hood HM I included a program of trampolining that I hoped would strengthen my legs sufficiently. As described in the recent post, the trampolining was not enough.  My brief experimentation with lifting free weights in early August has given me reason to expect that a systematic program of lifting weights after the HM is the best medium term plan.  But for now I have a little less than two weeks of tapering to make the best of my current situation.

In fact the two weeks taper period is perhaps the most important two weeks of a HM program.  Done correctly, it can potentially produce improvements of 4 or 5 minutes. This is mainly due to a recovery of the strength and coordination that has been impaired by the rigours of training.  The general principles of what must be done are fairly well established:  decrease training volume rapidly in the first week and more gradually in the second week; maintain intensity while decreasing volume; aim to polish the required neuromuscular coordination by short repetitions at race pace; get enough sleep and eat healthily.

These principles have largely been established in studies of younger runners.  It is reasonable to expect that they also apply to older runners, but the details of how they are to best applied have to be worked out taking account of one’s own strengths and weaknesses.  My major weakness is manifest in my clunky, aching legs.  My potential strength is my aerobic capacity and my fairly economical running style.   So this week the priority is balancing the need for recovery with the creation of the sharpness that comes from running at race pace or a bit faster, while avoiding injury.  Every step that I run this week must have a clear purpose directed towards these goals.  Almost every step I run will be either: warm-up, moderate tempo at around HM pace; striding-out for distances of 50-100 m at around 75-80 % maximum effort with floating between the stride-outs; or cool down.  This week and next I will not run a single step for the sake of achieving either distance or total accumulated volume.

But there is one other thing I will do.  After 36 weeks of fairly consistent running at slow or moderate speeds, there are dormant muscle fibres that need re-awakening and fine-tuning.  So my plan includes a weekly session of Pete Magill’s drills for older runners.  These are mainly playful skipping and similar movements that engage the various muscles required for fluent running.  There are 10 drills but it is not necessary to do all 10.  Six require relatively simple movements starting with  school yard skipping, moving on to high skipping, marching, foot shuffling, butt kicks and high knees.  The seventh in order of difficulty is ‘skip and kick’, which requires moderate hamstring flexibility, but I can do it reasonably well. Three of the exercises are quite demanding: long skipping in which the length of the hops is taxing; bounding which produces a hefty eccentric load on impact with the ground; and carioca, which involves exuberant hip swinging. In the video, carioca is demonstrated by Pete’s youthful, lithe and glamorous partner, Grace Padilla.  In the interest of minimizing risk of injury I decided to omit long skipping, bounding and carioca during this pre-race period.

After a rest day yesterday, today I did the first of the two drill sessions planned for this taper.  One crucial aspect of the drill session is interleaving the drills themselves with stride-outs to encourage incorporation of the recruitment of the muscle fibres awoken by the drill within a fluent running action.  So, after a 16 minute warm up that included 4 stride-outs, I did each of the seven selected drills, following each with a 50m stride-out.  After the completion of the drills and stride-outs, I then did 15 minutes of running at a relaxed but steady pace, not far below my intended HM effort, finishing with an easy cool down and gentle stretching of calf, hams and quad muscles.

It was a very satisfying session.  My legs are still a little clunky, but during the 15 minutes of steady paced running at the end, I could start to imagine myself running fluently again.  I feel that the taper has got off to a good, though perhaps unconventional start.

Progress

After a frustrating few years in which illnesses and an accident had frustrated my attempts to get fit, by the end of summer 2011, I was ready to make another start on the challenge of preparing for a marathon.  In the mid-summer months I had been running  at a gentle pace for an average of about 20Km per week without any problems, apart from the rather dismal evidence that my muscles had atrophied following the protracted arthritis that had blighted much of the preceding eighteen months.  It appeared to be a good time to get started again.

Laying a new foundation

After the midpoint of the seventh decade, getting the body used to working again is not easy. The goal of running a marathon in 2012 that I had set a few years earlier, would of course have to be deferred.  As I re-examined the situation at the approach of autumn 2011, it was clear that the medium term goal should be to run a half marathon in the autumn of 2012.  The first step was to do a few months of general conditioning.  This included two weeks of running on the mountain trails of the Sierra Nevada in southern Spain.   The second step was to see if I could get at least a modest level of speed back into my legs; at least enough to run a 5K in 25 minutes.  After adding some interval sessions to my program, I lined up for my inaugural run in the recently founded local parkrun at Colwick lakes, in early November.   I was delighted to cross the line in 24:48 but a little rueful to acknowledge that this was a pace that I would once have regarded as a little more than a jog.  In late November and December I focussed on increasing the distance of my longer runs, and was satisfied to run 21Km at an average pace a little faster than 6 min/Km before Christmas.   I just had to accept that numbers that might once have been minutes per mile now measured minutes per Km.

Base-building

I started the New Year with a few weeks of easy running and then in mid-January, embarked upon the first of two 18 week training blocks.  The first block would be base building, consisting largely of low-aerobic running, with occasional progressive runs to avoid getting bogged down in slow plodding mode.

By the end of the 18 weeks of base-building I was running over 80 Km per week – the greatest weekly volume I had achieved for more than forty years.   Again I tested myself over 21 Km and was reasonably satisfied to find that I could maintain a pace around 5:40/Km without excessive effort.

Race- specific training

Now it was time to plan the next 18 week block of specific preparation for racing a half marathon. After the vicissitudes of the previous three years, I was very uncertain in setting a target time.  My dream was to break 100 minutes.   The objective evidence suggested that 108 minutes was more realistic. I was still finding a pace of 5 min/Km very taxing.   Nonetheless,  I drew up a plan designed to get me across the line in 100 minutes in the Robin Hood Half marathon on 30^th September   The plan called for a total volume of around  1100 Km ,  including 17 long runs (15 Km or more) and 37 fairly intense runs – progressive runs,  tempo runs and interval sessions.  As the target time demanded sustaining a pace of around 4:44 per Km for 21.1 Km, the key sessions would be long runs in which I aimed to achieve a pace around 4:44 for the final 5 Km.

In light of the persisting lack of leg muscle strength, I also included regular brief sessions on the trampoline in the hope that this would provide a relatively gentle form of plyometrics that would help my legs adapt to eccentric loading. In addition, the program included some body weight resistance exercises but I had decided against using weights because my left wrist was still painful following the arthritis of the preceding eighteen months.  Any load that applied a twisting force to my wrist was excruciating.

The plan got off to a shaky start. In the first week I felt overwhelming tiredness; my legs were sluggish and clunky.  However, I was not too concerned.   The weekly volume of around 80 Km/week  in the final stages of base-building had been appreciably higher than the average of 64 Km per week that I planned for the next 18 weeks, so I was content to make the transition to the more intense race-specific program with a fairly easy recovery week.  After a week of running easily, apart from one mildly demanding 8Km progressive run, I was a little dismayed to find that the following week my legs still felt sluggish.  My heart rate variability measurements provide no evidence of generalised ‘whole-body’ stress.  It was just my legs that were clunky, so I pushed on with the planned program.      To reduce the effect of repeated jarring impacts on my legs I replaced some of the planned progressive runs by interval or tempo sessions on the elliptical cross-trainer.  In the next few weeks I completed all the intended sessions, but I could not achieve the target paces.   It was becoming increasingly apparent that the 100 minute target was unrealistic.

The hopping test and a re-evaluation

By mid-July it was clear that my legs muscles were too badly atrophied to sustain the modest speeds specified in my plan.   At that stage I repeated the hopping test that I had used in the past to assess my leg strength.  The test entails measuring the distance covered in 5 consecutive hops on one leg.  When I had last carried out this test in February 2010, I covered 9.71m with 5 hops on the left leg, and 9.24m on the right.  The shorter distance on the right was consistent with the fact that in previous years the arthritis has usually affected my right knee more than my left.  In contrast the recent episode had attacked the left knee mote aggressively, so I expected the right leg now to be the stronger of the two. Indeed this prediction was confirmed, but what I hadn’t predicted was how much both legs had deteriorated.   Now I could only manage 7.77m on the right and 7.45m on the left.  There had been a decline of more than 20% in 30 months.  It was clear that the trampolining was not enough to reverse the decline.

A change of plan was called for, but I did not want to change too radically.  I cut back the intensity of the running while maintaining the number of sessions of each type, and introduced some resistance work using weights.  I was delighted at this time to receive an email out of the blue from Kieren, a runner whom I knew only as the author of a blog that had been one of the major inspirations that led me to take up blogging five years ago.  Kieren has suffered an injury around that time and I lost track of him after he had stopped blogging – though I had eventually discovered that in more recent times he was posting reports on the Fetch web-site about his progress using weights, especially squats, to get back into shape.   He had meanwhile stumbled across my blog and emailed me with a comment about heart rate.  We got into conversation about the benefits of squats for strengthening legs and core.  I adapted my program in light of his advice, while taking great care to avoid any twisting forces on my vulnerable left wrist.  I was delighted to find after 4 weeks, that not only was there an appreciable improvement in my speed  during stride-outs at 80% maximum effort, but my left wrist was also much less painful.  Apparently my stronger forearm muscles were providing more support for my wrist.

Re-focussing on running

At that stage, with less than 6 weeks remaining before the HM, it was time to put all my efforts back into running.   Despite the appreciable increase in sprint speed, as soon as I increased the training volume again, my legs felt sluggish and I continued to find it difficult to achieve paces much faster than 6 min/Km during long runs or 5 min/Km in tempo runs.  Nonetheless, I persevered with the sessions I had planned.  A sustained effort to strengthen my legs would have to wait until after the HM.

By end of this eighteen week race-specific training block I had covered 1040 Km (about 90% of the planned total volume); 16 of the planned 17 long runs and all 37 of the moderate to high intensity progressive, tempo and interval sessions, though almost half of these were performed on the elliptical.  The major shortfall had been in the paces achieved during both the long runs and the tempo sessions.

My current state

My basic aerobic fitness appears to be good.  In a relaxed low aerobic run a week ago, I covered 12.5Km at an average pace of 5:49 min/Km with an average heart rate of 107 b/min – that corresponds to 629 b/Km, and suggests that my heart is pumping well and delivering an adequate supply of oxygenated blood to the muscles; and that my slow twitch fibres are fairly well endowed with mitochondria.  But I simply cannot sustain paces any faster than 5 min/Km for an appreciable distance.   Despite being adequately supplied with oxygen, muscles cannot generate the required force if the fibres are not strong enough.   I appear to be too reliant on a sparse cohort of anaerobic type 2 fibres to achieve faster paces.  The major problem is probably a lack of aerobic type 2 fibres.

I am now at the beginning of a two week taper, during which I will reduce the training volume while maintaining the number of moderately intense sessions.  I hope that as the accumulated tiredness dissipates, my neuromuscular coordination will improve, and my speed will increase at least a little.  I will not make any precise forecast about race time until I see how my legs respond to the taper.  It is clear that 100 minutes is out of the question. On the other hand, I will be very disappointed if I cannot improve at least a little on the 108 minutes I recorded in the Keyworth Turkey Trot two years ago.   But whatever I achieve in two weeks time, it is clear that after this race is over my major task for the next few months should be a serious program of resistance work to reverse the atrophy of my leg muscles.

Training to increase sprinting speed

The issues raised by Klas in his comments on my recent post on Usain Bolt’s sprinting style have led me to wonder just what it is that determines peak sprinting speed and what a runner might do to increase sprinting speed.

The key relevant scientific study is the investigation of 33 physically active adults (aged between 18 and 36) of varying sprinting ability, published by Peter Weyand and colleagues from Harvard University in Journal of Applied Physiology (J Appl Physiol, 89: 1991–1999, 2000).  They measured characteristics such as cadence, time on stance, swing time and ground reaction force observed across a range of speeds up each individual’s top sprinting speed.  The range of top speeds extended from 6.2 metre/sec up to 11.1 m/sec.  They observed that the faster sprinters exerted a stronger push on the ground while on stance and concluded ‘runners reach faster top speeds not by repositioning their limbs more rapidly in the air, but by applying greater support forces to the ground’.

I agree with their conclusion, but closer inspection of their data leads me to a slight modification that might have important implications for how a runner should train to increase speed.

Limb repositioning time

First let us consider the time taken to reposition the swinging leg from its position behind the centre of gravity (COG) at lift-off from stance, to a position a little ahead of the COG at foot-fall.  This is the swing time.  It embraces two airborne intervals and a period of stance on the other leg.  Perhaps surprisingly, the swing time at top speed varies very little between runners of markedly different sprinting ability.  The average swing time of the 33 runners was 0.38 seconds with only weak evidence that faster runners have a shorter swing time.  For comparison, the average swing time of the three medal winners in the male 100m at the 1996 Olympics was 0.33 sec.  However, there is little evidence of a consistent trend across the range of sprinting ability.  For example, the slowest of the 33 individuals studies by Weyand had a swing time of 0.34 sec despite running only a little faster than half the speed of the fastest runners.

Although faster runners spend less time on stance, because their speed is greater, the foot gets left further behind during stance. Typically, a slow runner has to move the foot forward by about 85 cm relative to the COG during the swing, while the fastest runners have to move the foot forwards by about 105 cm.  Thus, the faster runners do swing their foot forwards a little faster. For an elite sprinter it is worthwhile expending some effort on improving swing dynamics, for example by flexing the knee to create a short lever arm at mid-swing.  However, this is only fine tuning – perhaps it might make the difference between a gold medal and fourth place, but it is not likely to produce the magnitude of improvement that might encourage a recreational distance runner to choose to become a sprinter instead.

It is interesting to wonder why swing time at top speed varies so little between elite sprinters and non-athletes.  It appears that most of the gain a  faster sprinter derives from increased ability to reposition the foot rapidly relative to the COG is required to compensate for the modest increase in the range of the swing required at higher speed.  It appears to be impossible to get swing time appreciably below a third of a second.  Although the swinging leg is not merely a passive pendulum it is hard to drive it much faster than its natural swinging rate

Time on stance

The strongest predictor of top sprinting speed is ability to get off stance rapidly.  In Weyand’s study, the slowest sprinters spent 0.135 sec on stance while the fastest spent about 0.09 sec on stance.  Furthermore, there was a very consistent trend for decreasing time on stance to predict faster top speed, across the full range of sprinting ability. The correlation between stance time and top speed was 0.76.

Shorter time on stance is associated with stronger push against the ground.  The average vertical ground reaction force (vGRF) during stance increased from 1.9 times body weight to 2.4 times body weight, although the relationship was not quite so consistent across the range of top speeds.  The correlation between average push and top speed was 0.62.  Thus the average vGRF while on stance was not quite such a reliable predictor of top speed as stance time.

It is of interest to note that because stance time decreases as strength of push increases, the impulse delivered (product of force by time for which the force acts) varies relatively little between the slower sprinters and the fastest.  The vertical impulse was 2.49 newton-sec at a top speed of 6.2 m/sec and 2.25 newton-sec at a top speed of 11.1 m/sec. As the vertical impulse determines how much upward momentum is imparted to the body, it determines how high the COG is elevated between mid-stance and mid-flight. .The peak elevation of the COG was marginally lower in the fastest spinters.  The precise gain in elevation from a given impulse depends on the shape of the relationship between force and time while on stance. . For a forefoot runer it is approximaltey sinusoidal and in this case, the range of vertical oscillation of the COG was 5 cm at 6.2 m/sec and 4.3 cm at 11.1 m/sec.

Estimated values for slowest and fastest runners based on linear trends across the group of 33 runners. *The calculation of peak vGRF and elevation assumes a sinusoidal variation of vGRF with time during stance – typical of a forefoot runner

Conclusion

These observations indicate that if one wants to sprint faster, one should aim to increase push and decrease time on stance.  Although these two variables are related, in fact the decrease in time on stance is a stronger predictor of peak speed than the magnitude of the push.  This is not surprising because decreased time on stance directly reduces braking, which leads not only to increased fuel efficiency, as discussed in my post on 16th January, but also to more efficient utilization of peak power.

It is necessary to have strong leg muscles to get off stance quickly, so it is worthwhile training so as to increase leg strength.  As eccentric contraction is required, plyometrics are potentially helpful. However, the fact that the ability to get off stance quickly is the strongest predictor of top speed, suggests that one requires not only adequate strength but also good coordination of the muscles so as to capture impact energy as elastic energy and then release that energy in a smoothly coordinated way.  This conclusion is similar to that reached on the basis of considering the style of Usain Bolt.  If I want to increase my sprint speed I should focus not only on increasing my strength, but also my coordination.

I suspect that genes and development during infancy play a large part in determining how quickly a person can get off stance.  Nonetheless, the fact that top speed decreases with age demonstrates that top speed is not fixed, and suggests that a training program aimed at producing changes opposite to those produced by aging might produce an increase in sprinting speed.

How might I increase my coordination?  Plyometrics are likely to increase coordination in addition to increasing strength, though they are risky, and should be performed in moderation.  A more direct focus on coordination might be worthwhile.  Coordination depends on proprioception  (the ability to sense  where ones limbs are) and the ability to send messages from the central nervous system to the muscles with the appropriate  precise timing.  I believe that drills such as ‘change of stance’ are likely to be an effective way to achieve this

Lessons from Ed Whitlock, Fauja Singh and Renato Canova

In a comment on my post two weeks ago about my first interval session since recommencing regular running after  series of disruptive misadventures, Thomas suggested that I would be better off forgetting about speed workouts and doing as much easy paced, aerobic running as my legs would let me, instead.   The debate about when to introduce speed sessions has been one of the most long-standing debates about training for distance running, and Thomas’ comment once again set me to weighing up the wisdom of my plan.

There is little doubt that before building up intensity, it is crucial to do enough low intensity running to condition sinews and muscles to protect them against injury.  At the end of the summer, I had gradually built-up volume with low intensity running – enough, I think, to prepare my sinews and muscles for moderately intense interval sessions provided I keep the number of reps low enough to avoid serious fatigue.   So the debate hinges mainly on the question of whether a high volume of low intensity running is essential to build a sound aerobic base, and the related question of whether speed sessions help or hinder base-building.

Lessons from Ed Whitlock

There is no doubt that at least for some athletes, a large volume of low intensity running works well.  In the Toronto Waterfront Marathon earlier this month, Ed Whitlock set a new M80-84 world record of 3:15:54.  Whitlock is famous for training slowly – typically he runs 15-20 miles daily, in monotonous 500m circuits of Evergreen Cemetery near his home in a Toronto suburb, at 9 min mile pace.  While this pace is not all that slow for an 80 year old, compared with his marathon racing pace of 7:30 min/mile, 9 minute mile pace is fairly relaxed.   He only occasionally does intervals.

However I think that there are some additional aspects of Whitlock’s running history that need to be taken into account.  As a young man Whitlock was a fairly fast runner – competing with and occasionally beating some of the legendary figures of British distance running in the 1950’s.  When he took up running again in his early 40’s, while living in Montreal, he concentrated on middle distances.  In a Runners Web interview in 2003, he reported that this best times during those years in Montreal were 1:59.9 and 4:02. He described his training as ‘a fair amount of road work but the serious stuff was track interval work outs under coaching supervision’.  I suspect that he built up some fairly powerful type 2a (aerobic fast twitch) muscle fibres in those sessions.   In more recent years, he has balanced his long slow training sessions with frequent races, and his racing paces are fast – typically under 6 minutes for a mile and around 6:50 /mile in 10K.   Frequent racing at these speeds no doubt keeps those type 2a fibres in good condition.

and from Faija Singh

The other amazing veteran performance in this year’s Toronto Waterfront Marathon was 100 year old Fauja Singh’s 8:11:06, also a world record.  The most impressive feature is not the time itself but simply that he is the first 100 year old to complete a marathon.  Fauja also trains fairly slowly – typical he run/walks 10-15Km a day, though he does do some track training and he holds the world M100 records for virtually all distances from 100 metres (23.14 sec) to the marathon.

Despite their predominantly high volume/low intensity training, both Ed Whitlock and Fauja Singh illustrate that if you want to sustain a reasonable pace over the longer distances as the years go by, it is important to maintain some speed in your legs.  I think the greatest enemy of speed in the veteran years is the loss of type 2a fibres.   For a runner whose goal is to run a reasonably fast race over any distance shorter than an ultra-marathon, building up  the type 2a fibres is almost as important as building up the type 1  (slow twitch) fibres.  The specialist ability of the elite marathon runner is the ability to maintain a pace at the upper boundary of the aerobic zone for several hours. This demands not only endurance but enduring muscle power.

Renato Canova

Perhaps the most successful marathon and half-marathon coach of all time is Renato Canova.  His protégés include Moses Mosop, Florence Kiplagat, Abel Kirui and Wilson Kiprop.  Not only has he coached some of the world’s finest half marathon and marathon runners, but he has also been more prepared than any other leading endurance coach to discuss his ideas with the running community, most notably though his frequent and comprehensive contributions to Let’s Run forums.  He claims that his principles are based on observation of many leading athletes of the past two decades; extensive discussion with other coaches and a good grounding on science, particularly detailed evidence about energy metabolism derived from lactate testing in many athletes.

A key feature of Canova’s approach is periodization that leads to a final period of training that is specific for the target event.  In the case of marathon training, the goal of the specific period is to develop the capacity to maintain marathon pace for increasingly long distances.  However long runs at MP are potentially stressful and therefore, must follow earlier phases that are designed to build an adequate foundation for this demanding final phase.  Of course most coaches advocate some form of periodization which starts with base building and leads to more specialized training.  However, there is a crucial conceptual difference between Canova’s periodization and the periodization recommended by a coaches such as Maffetone and Hadd,.  Whereas Maffetone and Hadd argue that exceeding anaerobic threshold can interfere with the building of an aerobic base, Canova does not and therefore he is more inclined to recommend a greater mixture of different types of session within each phase of the periodization.  As I have discussed in previous posts, there is only a little evidence that speed sessions might damage aerobic fitness, but substantial evidence that training at the upper end of the aerobic zone is an efficient way to produce increases in aerobic capacity.

The four phases of marathon preparation identified by Canova are a general phase in which the emphasis is on developing an all-round base; a foundation phase designed to build endurance via fairly high volume of low intensity running.; special preparation which increasing the capability to maintain marathon pace and a little faster; specific training in which the goal is to accustom the body  to running at marathon pace or even a little faster for distances in the range 25-35 Km.

Looking backward to move forward

For present purposes, I am interested in the general phase, whose goal is the development of an all round base.  I think this is the phase in which each individual has to weigh up his or her own current strengths and weaknesses, based on a life-time history of running.  My own personal experience suggests that for me, a crucial component of building an all round base includes building up muscle coordination and strength.   This is the foundation for ensuring that even in the subsequent higher volume, relatively low intensity phase I can maintain a reasonable pace, bearing in mind that beyond that phase comes a specific training phase in which the body must become accustomed to sustaining marathon pace for 25-35 KM.

Over forty years ago I became a marathon runner almost by accident.  At that time, I was involved in a fairly wide range of interests and activities, one of which was club level track athletics.  My main event was the 5000m but I wasn’t especially gifted.  My principal objective at interclub meetings was gaining points for my club.  As a result I ran in events as diverse as 400m hurdles, 3000m steeplechase and 5000m, though I cannot remember ever winning any interclub event, at any distance.   The majority of my training consisted of tempo runs and fartlek around the local suburban streets.  During the winter I ran cross county races on weekends when I was not involved in other activities, such as mountaineering.  One year in the late 1960’s I entered a marathon, with very little specific marathon preparation.  In those days there were few marathons and this one happened to be the South Australian state championship.  Rather to my surprise, I won it.  In retrospect, I think the conclusion is that while I have very limited natural speed, I have a modicum of natural endurance.  Whether this is a product of my genes or the fact that I used to run to and from school as a youngster, I do not know.  Whatever, the origin of my endurance, it appeared that the main requirement to allow me to put this endurance to use in a marathon was enough tempo running and fartlek to compensate for my lack of natural speed.  I only ever ran about four marathons in those days.  I do not have a record of my best time but it was around 2:25.

Almost forty years later, in my late fifties, I decided that it was time to get fit again.  Without fully appreciating the effort it would require, I decided to prepare for a marathon at age 60.  However I was dismayed to find that whereas four decades previously my tempo pace was around 5:30 to 5:45 minutes per mile, and I had rarely trained at paces slower than 6 minutes per mile, now it was a struggle to run faster than 6 min per Km.  So I decided my first task was to get my tempo pace up to something between 4 and 4:15 minutes per Km.  After about six months of tempo sessions, fartlek and a few interval sessions, I did a time trial over a 10 K cross country route in 41 minutes.  I was a bit disappointed to fail to break 40 minutes but nonetheless turned my attention to re-establishing my endurance.    For 5 months, I averaged only about 30 miles per week, but did include three long runs of 20 miles or more.  At that stage, I entered a marathon to assess my progress and allow me to set a reasonable goal for my intended M60 marathon attempt the following year.

In my previous experience, at the start of a marathon the entire field formed no more than two or three rows across the roadway.  In the intervening decades the character of marathon races had been transformed almost beyond belief.  I now found myself engulfed in a vast throng of runners in diverse outfits progressing at diverse speeds.  After feeling trapped at a snail’s pace for the first mile I broke clear of the melee with a crazy burst of speed and did not settle to a sensible pace until after three miles.  I reached the halfway mark in 93 minutes, feeling fairly comfortable.  However by 20 miles I was paying the price for my crazy escape from the melee at the beginning, and in the final few miles I struggled even to achieve 10 minute mile pace.  My finishing time was 3:27:35.  I was disappointed by my poor pace judgement but considered that the following year, after my 60^th birthday, it would be feasible to aim for a time around 3:15.  Unfortunately, my long standing asthma came back with a vengeance the following year and I gave up training.

A couple of years later I made another attempt to get back into training but was once again diverted by several misadventures, including a rather nasty fall earlier this year.  Now, I am starting again.   But now, in my mid sixties, I am acutely aware of how much muscle strength I have lost in the past few years.  Once again it is an effort to run much faster than 6 min/Km.  My past experiences suggests to me that the highest priority in my  general conditioning phase is to get some speed back into my legs.  Then I can embark on some high volume, lower intensity workouts, with the   expectation that even when running at lower intensity, I will be able to maintain at least a moderate pace, in preparation for the phase in which I will try once again to accustom myself to  sustaining marathon pace for long distances.

My current program includes a weekly interval session or hill session, a progressive run or tempo run, and one longish run (typically 15 Km), together with some easier sessions to make a total of around 50Km per week.  I am also doing some trampolining – which I hope will prove to be a satisfactory substitute for plyometrics, but more gentle on aging legs.  I will persist with this program for at least 3 months.  My first target is a 25 Min 5K, and after that I will see how much further I can increase my pace.  I hope that this will allow me not only to get some speed back into my legs, but also give me some idea of what pace to aim for in a half-marathon in spring of 2012.

Last week I did a 4×1 Km session and was reasonably pleased to maintain a pace in the range 4:33 – 4:38 min/Km for each repetition, without pushing myself too hard.    So a 25 min 5 K appears within reach, but I will have to wait patiently to see what further gains might be possible.

Reality check

In the past 10 weeks I have run about 3 times a week on average, covering a total distance of about 280 Km in runs ranging from 3 Km up to 15 Km , across a variety of different types of terrain.   The most strenuous of these runs were on mountain tracks in the Sierra Nevada (in southern Spain, not California).  Mainly I have maintained a pace around 6min/Km, except in the mountains.  On a few occasions I have progressively increased pace to around 5:30 /Km along the riverside path near home.   I have kept my heart rate mainly in the range 75-80% of maximum.    Although my joints have felt rather clunky and my ligaments have felt stiff, my muscles have not complained too much.   So I decided today that it was time for a structured session with a specific target.

My major short term goal is to get some speed back into my legs.  My medium term goal is to run a reasonably fast 5Km, but because I have clearly lost a lot of fitness as a result of the misadventures of the past year, it is not clear what would be a reasonable goal.  However observation of my heart rate indicates that at a pace around 5:30/ km I am already in the mid to upper part of the aerobic zone, suggesting that a 25 min 5 Km would be a challenge at present.

For the next 4 weeks I will aim to do 5 sessions per week, including two moderately effortful sessions: an interval session (short or long) and either a tempo session at around 5:20 min/Km or a progressive run aiming to reach 5 min/Km pace for the final few Km.   The short interval sessions will be 400m repeats aiming for a pace around 4:15 min/km and in the longer interval sessions I will do 1000m repeats aiming for 5 min/Km.

Today, I was eager to see if I could sustain 4:15 pace during 400m repeats, so I decided on 4x400m.  Beforehand I used Google Earth to locate two trees 400m apart on the fields beside Fairham Brook.   However when I got there, it was not absolutely clear which of the many trees lining the brook were my 400m markers.  I set off on the first estimated ‘400m’, into a slight head wind across a grassy surface that was easy on the legs, though a little bumpy in places and definitely not ideal for fast running.  I was dismayed to find that my time was 112 sec.    I was already in the anaerobic zone,  and it was clear that running any faster would be unreasonably stressful.   After 3 minutes of easy jogging my heart rate had fallen from 95% of maximum to around 75%; I had intended to get it down to 70% before the second 400m, but even after 5 min of easy jogging it remained at around 70% so I set off, with the breeze behind me this time, but again was disconcerted to find that my time was only marginally less.  Once again I was well into the anaerobic zone.

I completed the four  ’400m’ runs, each in a time in the range 110-112 sec, and on each occasion, well into the anaerobic zone.   On each occasion my heart rate settled to a level around 75% of max after 3 minutes of jogging at a pace which would normally produce a heart rate around 60% of max.  It was clear that I was accumulating a substantial amount of lactate during the 400m runs.   It seemed that I was even less fit that I had anticipated, and that a 25 min 5K would be out of reach for the near future.  After a careful look at my ‘400m’ marker trees, I set off for home at a gentle jog, but the continuing elevation of heart rate and respiratory rate demonstrated that I still had appreciable acidity in my blood stream.

When I got home I made a closer inspection of the trees on Google Earth.  Marrying the Google Earth aerial view with my ground level observations, it was clear that I had misidentified my intended marker trees.   In fact the markers I was using were 445m apart, so my true times were in the range 99-101 sec per 400m, corresponding to 4:10 min per Km.   I had achieved a pace slightly faster than my target pace of 4:15.  However it had been quite effortful.  Most noticeably, my ability to clear acidity from my blood stream is very poor.   Fortunately, that is perhaps the most readily trainable of the various metabolic adaptations required for 5Km racing, so all in all, it was a good opening session of my campaign.  A few hours afterwards I did a bit of bouncing on the trampoline and my legs felt reasonably springy, so I do not anticipate appreciable DOMS tomorrow.  Next week’s interval session will be 4x1000m aiming for 5 min/Km pace.  That will give me a clearer idea of just how near or far I am from a 25 min 5K.