The big question

In recent weeks I have been posting my thoughts on the risks of long term muscle damage from a training program that includes a large eccentric load. In response to my recent posting ‘sloppy snow and reactive oxygen’, Ewen has posed the big question:

‘Regarding the ‘damage’ caused to muscles by excessive aerobic metabolism… do you think this is good evidence for a training program (for older athletes) that limits aerobic running and promotes higher quality running? When I say “limits”, I’m thinking a runner who might have run 80k per week in their youth, now runs 50-60k, but with higher quality. ‘

The answer is that I have not yet found enough ‘good evidence’ to justify firm conclusions, but I have found some thought provoking information based on scientific studies that allows one to make a reasonably well informed guess.

One problem with scientific studies is that at best they provide information about what happens in a particular group of runners who represent only a small selection of the huge range of variability within humankind; variability that arises from variation in genes and variation in life experiences, including training history. So each individual has to balance the scientific evidence with their own experience.

I think that there is enough evidence to justify the conclusion that abrupt increases in training load or excessive training loads can produce long term damage even in the absence of overt acute injury. It is plausible that the chronic leg weariness might be a marker for long term damage. Therefore, whatever training plan one adopts, I would strongly recommend increased recovery time whenever persisting leg weariness develops.

As to the question of whether a smaller amount of high intensity training is preferable to a larger volume of low intensity training, the answer is not clear. For me, in recent times a weekly volume of 80Km or more results in persisting leg weariness. However, in ‘oldies’, fast running without adequate preparation by gradual build up of intensity almost certainly creates risk of acute injury, and probably causes long term damage.

The elliptical cross trainer appears to require less eccentric contraction and produces less muscle aches and pains, and less persisting leg weariness, that running sessions of equivalent intensity. My own experience when I recommenced training early in 2007 is that a 6 week program based almost entirely on elliptical training produced a substantial improvement in my running performance over a distance of 6Km. However, I do not yet have good evidence that elliptical cross-training produces further improvement in running performance after the easy initial gains.

So my own current plan is to do a mixture of moderate intensity running sessions and somewhat higher intensity elliptical sessions, leavened with some easier running sessions. I will also monitor my progress to determine whether or not my strategy is producing improvement.

The question of how best to monitor progress is not easily answered. I have devised what I believe is a good test of aerobic fitness on the elliptical. I measure my heart rate over a range of power output values – this gives fairly good reproducibility from day to day, though the reproducibility is a little confounded by the daily variations in my asthma. For a test of aerobic fitness when running I will probably employ a version of the Hadd test (or the similar Maffetone test) but at present I face the difficulty that my usual running terrain is cross-country and varies according to weather.

Fortunately, I can afford to be patient as my goal is to sustain, and hopefully improve, performance over a period of 5-10 years.


2 Responses to “The big question”

  1. The big question « Canute’s Efficient Running Site | Says:

    […] more:  The big question « Canute’s Efficient Running Site Share and […]

  2. Ewen Says:

    Thanks Canute. Persistent leg weariness is something many higher mileage runners can relate to (although I’m not sure if my 90k per week qualifies as high mileage).

    I can recall runs where I had intended to run at ‘upper aerobic’ pace, but the legs didn’t want to push the HR into that zone. Maybe as a ‘one-off’ that’s no cause for concern, but a number of days in a row of that feeling is probably a sign of persistent weariness.

    I’m inclined to experiment with the number of easier days (usually 2 at the moment, but sometimes 1) between harder sessions. 2 and sometimes 3 might be better (for me). I’m also inclined to experiment with having 2 very short, very easy runs – am and pm (2 x 3 or 4k) as a recovery day – which might be better than one easy run of 6 or 8k).

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