Responses to training and to over-training

I am now tapering for the Robin Hood half marathon, five days away.  After a frustrating start to the year, in which a recurrence of arthritis limited my training for a few months, I have been able to train consistently for six months.    I have achieved a greater training volume in those six months than I managed in the equivalent period last year, but frustratingly, my pace during tempo runs and progressive runs is slower this year than last year.    In the event, last year I performed better than appeared possible in the light of my prior training paces, though at the cost of a  somewhat painful final few kilometres.  Again this year I will be hoping that I can lift myself to a higher level on race day.  Despite the lower level of aerobic fitness this year, I am hoping that the greater training volume will have produced greater endurance.   So I will be approaching the race with modest optimism that I can achieve a time near to last year’s time.

However, Sunday’s race is merely a stage in my campaign to run a respectable marathon at age 70.  At this stage it would be premature to estimate a target time for a marathon in three years time.  This year’s Half Marathon will provide something of a guide, though in fact my most important goal this year has been to establish that I can maintain an adequate training volume over a period of 6 months.  Because my aging legs cannot cope with too much stress, I do about 20% of my training on the elliptical cross trainer.   In the past 6 months, I have averaged 36 miles of running per week, together with an additional 1000 Kcal/week on the elliptical (equivalent to approximately 10 miles/week), giving an average weekly training volume equivalent to 46 miles per week.   Although modest in comparison with a volume exceeding 100 mpw achieved by many younger marathoners, the key question is how to determine  the optimum amount for me.    The short answer is the that optimum amount is the amount that maximizes my response to training in the short term while building a base for future years.

What determines the response to training?

Four things determine the benefit you get from training.

  1. Genes
  2. Life-time training experience
  3. The type, intensity and volume of the training
  4. Current level of stress.


There is little that we can do about our genes, but it is nonetheless, worthwhile reviewing the issue of genes briefly.  The marathon performances of my younger days suggest that I was blessed with genes providing at least a moderate natural facility for distance running and also with the capacity to profit from training.

However in my present situation there is a third aspect of genetic endowment that matters: my ability to withstand the ravages of age.  My parents both enjoyed moderately good health into their 80’s, so I have probably at least an averagely good selection of genes for longevity.  The evidence from my own health so far is equivocal.  Throughout my sixties I have suffered several health problems that have confounded any attempt to answer the question of how the tissues of my body are aging.  These minor illnesses in themselves might be an indicator of increasing vulnerability to deterioration, but give little indication of widespread deterioration.  In light of the fact that I have been able to train consistently for six months, my performance next Sunday will be potentially a good measure of the underlying rate of deterioration, uncontaminated by illness.    To match the rate of deterioration predicted by WAVA, I can afford to drop 1 minute compared to last year’s HM time of 101:50. On present form, even 102:50 will be a challenge.  However, if possible I would really like to set the clock back at least a little.   My gold standard target is 100 minutes and silver standard is last year’s time: 101:50, though realistically I should be very pleased even to achieve 102:50.

Life-time training experience

In the short term, there is little I can do to alter life-time training experience, but in regard to the medium term future, there are important issues to consider.  I suspect that running to and from school over 60 years ago, got me off to a good start.   However the more pressing issue at my current age is the question of whether a large annual training volume at this stage will actually hasten deterioration.  Excessive training can lead to chronic inflammation that is likely to damage tissues, possibly irreversibly.   It is likely that a range of factors, including not only genes and past experience but also current lifestyle factors, especially diet, influence this.  Thus, the question of how much training an individual can tolerate is likely to differ between individuals but is not necessarily immutable.   But whatever my current ability to tolerate training might be, monitoring response to training to detect signs of over-training is likely to be crucial.  I will return to this when addressing the effect stress in greater detail.

The type, intensity and volume of the training

Not only volume of training, but also type and intensity play a key role in shaping both the  immediate response and also the long term effects of training.  The pros and cons of different training regimes is too large a topic to deal with here, but it is perhaps pertinent to note that many athletes who have enjoyed years of high-level performance adopted a periodised program along the lines advocated by Arthur Lydiard, with a limited period of high intensity training and competition following a period of base-building in which the emphasis is on large volume of training at modest or low intensity.   I started my current HM campaign with a period of Lydiard-style base-building, and am confident that this was beneficial

Current level of stress

Again we are brought back to the key issue of stress.  As already discussed, avoiding cumulative tissue damage due to chronic inflammation is likely to be a key to the longevity of an individual’s running career.  It is also a key determinant of the short term response to training.

It is widely recognised that the benefits of training arise from a training stress followed by an adaptive response during the recovery period.  So stress is an essential element of training.  The stress includes microscopic local trauma to body tissues including muscle fibres and other connective tissues, and also increases in stress hormones that exert a widespread influence throughout the body.

Microscopic damage to muscle fibres activates satellite cells, which are a type of stem cell that when activated combine with muscle fibres to extend and strengthen them.   Thus in the short term heavy exercise results in loss of strength, but provided recovery between sessions is adequate, there is an overall upward progression.   On the other hand, if recovery is not adequate, there is a risk of a downward spiral.

In the case  of the hormonal responses, the increase in the stress hormone cortisol  promotes a physiological state that mobilises body resources in a way that is helpful in the short term, but potentially damaging in the long term.  The benefical short term effects include mobilisation of glucose and fats to fuel activity, but in the longer term, the result is muscle breakdown and deposition of fat.  Cortisol has anti-inflammatory effects which in moderation tend to be helpful, but if excessive or prolonged, weaken the immune system.  The mechanisms that determine the balance between the beneficial and harmful effects of inflammation are complex and remain something of a mystery.  But, at least one thing is clear: sustained stress leads to damage to many tissues of the body.  Fat is deposited around the viscera; chronic inflammation damages heart and skeletal muscle.  Adequate recovery is essential, both for the sake of a constructive medium term training benefit, and also for long term health and fitness.

Monitoring stress

Therefore, during the past six months, as I have attempted to establish the limit of training volume and intensity that my body can cope with, I have performed the sub-maximal tests described in my posts on 25th June  and 17th July 2013, on a weekly basis.  Apart from one episode early in the year, when I had increased the training load too rapidly, I have avoided the suppression of heart rate at sub-maximal effort which is a warning of impending over-training.  However on numerous occasions I have observed a moderate increase in heart rate at sub-maximal work rates, which I interpret as a sign of accumulating stress.  In response to this sign of accumulating stress I have avoided demanding training session for a few days, and the signs of stress have resolved.

The apparently clear-cut benefit of this strategy for regulating training stress is that this year, I have managed to cope with a training volume over the 6 months from April to September that is about 17% higher than in the equivalent period last year.   I am optimistic that this will stand me in good stead next year when I intend to train for a marathon.  However, as outlined in the introduction, the somewhat disappointing outcome is that I appear to have a lower level of aerobic fitness (indicated by heart beats/km at a given pace in the aerobic zone) than at this time last year.   Possibly this is due to a lower initial level of fitness arising from the disruption of training in the early months of this year.  Alternatively, perhaps in my determination to make up for lost time, I might have pushed myself too close to my limit and therefore gained less benefit from the training.  However, provided I have not seriously exceeded the limit, it is not unreasonable to hope that I might experience a similar improvement in performance during the taper this year as last year, and in addition will be able to draw upon enhanced endurance based on the greater training volume.   I will start the half marathon on Sunday with the goal of testing this optimistic speculation.

Ewen, I will do my best to earn that mansion in Forrest for you, but I fear that your garden shed might be at risk.

14 Responses to “Responses to training and to over-training”

  1. Steve Says:

    I wish you the best.

  2. Ewen Says:

    Thanks Canute. It was a clapped out garden shed that needed replacing anyway, so no great loss (should you not run 1:40). By the way, my Melbourne campaign has come to a shuddering halt with my failure to enter before the event filled up! Can’t believe that happened. Recent form indicates a time similar to last year (1:44) is all I could have expected. I expect my next HM attempt will be in April next year.

    Your monitoring of stress seems to be working well. A volume equivalent to 46 miles a week over an extended period is a good base indeed (probably equivalent to 60-70 miles by time for a young fast runner). Must say, the old fast runners are the ones that inspire me the most – like Ed Whitlock’s 1:38 half marathon at 82. Amazing. I’m sure you’re on track for a very respectable marathon at 70. Anyway, good luck on the weekend. Looking forward to reading your report.

    • canute1 Says:

      Thanks for your comment. It’s a shame that you missed the entry for Melbourne.
      Yes. Ed Whitlock is utterly amazing. I am intrigued as to how he adjusts his training volume. He does not measure distance or heart rate, though he does apparently adjust time spent running according to subjective assessment of how well his body is coping; and then he sets his pace for long races according to performance in recent shorter races.

  3. Robert Osfield Says:

    One thing I’ve noticed this year is that typically my HR beats per mile is higher for short runs this year compared to similar routes/distances than it was last year. However, my HR beats per mile is lower for long runs (2hr plus). If I were to just go by my short distance runs then I’d have to assume I’m less aerobically fit, but look at the long runs and I’d appear to have better aerobic fitness.

    From my ultra performances in the last two months I can say that my aerobic fitness appears to be solid, in particular my ability to burn fat looks to be much improved. This year I’ve run almost all my runs in fasted state, and my diet now contains less carbs than it did which I would expect will lead me to be burning more fat even on my short runs. Fat metabolism requires 13% oxygen than aerobic glycogen metabolism so perhaps the extra oxygen demand is what is leading to me requiring a relatively high HR during shorter runs. On longer runs my HR drift is not as significant as it once was, again I think this may be down to starting off burning more fat so my body doesn’t need to shift from carbs so dramatically.

    The reason why I raise all of this is perhaps you might be seeing something similar – an increase in HR beats per mile suggesting lower aerobic fitness, but in fact you might be burning more fat and thus requiring more oxygen and higher HR and actually have better overall aerobic fitness.

    The only real way to test all this out is to go do a full fitness test to find out just how much far/carbs you are burning at different paces. Without a similar test from last year it obviously won’t be possible to directly compare. Without such data perhaps the best you can do is go race and just see what happens.

    The more races you do the more data points you’ll have to use in working what all these various measurements mean in terms of real fitness. In the end though, being happy and healthy are far more important than a minute or two here or there in finishing time. So if you have fun this Saturday then job done. If you come close to your hopes w.r.t time then that’ll be a cherry on the top.

    Best of luck with the race.

    • canute1 Says:

      Thanks for those comments. I agree that burning a higher ratio of fat to carbs results in an increase in beats/mile at short and medium distances though it might lead to lower beats/mile in runs long enough to seriously deplete the glycogen supply. It is interesting to speculate that increased utilization of fats due to your diet contributed to your excellent performance in the Devil. In an ultra, efficient use of fuel is more important than efficient use of oxygen.

      I do not have any reason to think that I am using a higher proportion of fats this year. I have directed the race-specific training more towards increasing my ability to utilise lactate than towards fat utilization. In a HM, accumulation of acidity is likely to be the main limiting factor, though I am intrigued about the possibility that depletion of intracellular potassium might also contribute appreciably to fatigue. I hope that a modest amount of high intensity running in the final few weeks will have enhanced my capacity to pump potassium ions back into muscle cells.

      At this stage, I am not sure what to expect during the race. I will rely largely on how I feel on the day. Provided I feel reasonably comfortable, I am prepared to take a bit of a risk with the early pace. I will regard respiratory depth and rate as my most reliable guide, as I am fairly confident that I can hold a pace just a little below the second ventilatry threshold for 21 Km.

      • Robert Osfield Says:

        Agree with your assessment that for a HM you’ll be limited far more by fatigue when running close to lactate threshold than energy utilization. Tomorrow I’ll be running a trail 10k, so far removed than the 41 mile trail ultra I ran two weeks ago. Like your HM I’ll be far more limited by my ability to buffer and process lactate than my ability to burn fats. With a tempo run on Wednesday the only run in the last 5 months near 10k race pace I’m rather less prepared than yourself for the task in hand.

        My only hope is that my ability to process oxygen efficiently has been expanded by the demands of burning more fats so I’ll have a bit more headroom before I go anaerobic. Rather than solid science I think we have to put this under the banner of “find any positive you can find” and run with it 🙂

        I really do hope you have a great run tomorrow. I’m hoping for a sub 41 min time, if you can beat my time + 60 minutes for the HM then we can declare you the virtual race winner!

    • canute1 Says:

      It is an interesting observation that a large volume of low aerobic training leads can be effective in improving beats/mile across the entire aerobic range, extending from the lower aerobic zone range (where fat utilization is maximal) to the upper aerobic zone (where ability to handle lactate is crucial). It is not uncommon for recreational runners to achieve a 10K PB during low intensity base- training. In part the benefit across the full aerobic range is due to the fact that training in either lower or upper zone improves by capillary density and aerobic enzymes, which are involved in the utilization of both glucose and fats. However it is an interesting question whether strategies that a specifically intended to improve fat consumption rather than glucose consumption (such as training in a carbohydrate depleted state) can also improve capacity for working at the upper aerobic level, where glucose is usually the main fuel. There is reasonably good evidence that this can happen. I suspect it is because training in a carbohydrate depleted state actually enhances the body’s ability to use carbohydrates efficiently.

      So there is reason for hoping that your current level of fitness for ultra running might facilitate a fairly good 10K. I think that to achieving one’s peak performance at 10K also requires developing the type 2A (aerobic fast twitch) fibres; but hill running can be quite effective for this. So provided you have done some sharpening up to re-establish fluency at 10K pace, it is reasonable to aim for a good 10K time.

      We both approach the weekend not quite sure how well prepared we are for our events. I accept the challenge of achieving your 10K time + 60 minutes. Even though we are now competing, good luck. The dream ticket is 39:59 for you and 99:58 for me (and a mansion for Ewen)!

      • Ewen Says:

        Thanks Canute. 99:58 and a mansion in Forrest — not too much for us to ask, surely!

      • Robert Osfield Says:

        My Trossachs 10k time was 40:54, 19 seconds slower than my PB for the route. Pretty pleased with my performance as had so little race specific prep and only two weeks after an ultra.

        Might even had got a PB for the route if I hadn’t dawdled at the start – I arrived from my warm up run at the back of the field and the start happened immediately (a minute early by watch) and caught me rather un-prepared. A walking start followed by a jog through the tail enders for quarter of mile before I could start to get properly into race pace.

        So… now we wait for Canute’s reply… will he beat 1:40:54 and win the virtual race??? Fingers crossed the next blog post will be a triumphant sub 1:41 time.

    • canute1 Says:

      Well done. You have set me a daunting target.

    • canute1 Says:

      Robert, you win our competition- congratulations – and Ewen, I am afraid you have lost your garden shed – sorry, but I doubt that I could have done much better.

      I started at 4:53 /Km (103 min HM pace) for the first few Km, but it was clear by 3 Km that I would struggle to maintain that pace. My legs were not strong enough. In an attempt to reduce the impact forces on my legs, I increased cadence to over 200 steps per min for much of the journey, but my pace gradually ebbed away as my stride gradually shortened. I finished in 107:52 (unofficial). I will add a few more details in a blog, but that is the main story.

      • Robert Osfield Says:

        Well done for finishing and in a very respectable time too. It suggests that should be capable of a sub 4 hour marathon when you decide to move up the distance.

        However, I am little bit gutted for you that you didn’t pull a faster time out of the bag. I have been routing for you achieving what you wanted to achieve for the past six months so it’s a shame to not see it happen.

        Your performance is still a great achievement and inspiration for others wanting to keep healthy and moving efficiently throughout there lives.

  4. Lessons from enduring masters marathoners | Canute's Efficient Running Site Says:

    […] over-training including the role of cortisol on several occasions previously (e.g. here and here). In summary, effective training achieves it benefit by stressing the body in a way that elicits an […]

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