Richard_ wrote:
I believe and research supports that the people recover at different rates. Some recover fast, some slow. I recall a study where one subject recovered in a matter of hours while others took 3 days to recover. I've seen studies where it took 7 days for some subjects to recover. So, if people recover at different rate then how frequently should each individual train.
Do you have a citation for said studies showing, presumably great, differences in recovery rate in equally trained runners? Have you considered that the more a person trains, the better s/he may recover from training. You assume falsely, it seems, that a person’s “recoverability” is fixed.
First, you need to define the population you are speaking of. I’ll assume you’re talking about open-aged runners in good health, all equipped with two lungs and two legs.
I do believe “hardiness” varies to some extent, even among runners of similar age and health, but not nearly to the degree that would allow one to deduce that 3 runs per week is appropriate training for any significant number of runners. The difference in hardiness between subjects would have to be freakin’ huge for a person to be at his or her maximum training load at only three days of running per week, when we know daily training benefits a great deal of non-elite runners. People aren’t that dissimilar. Your dose-response theory simply doesn’t extrapolate so far as to allow your conclusions to be valid.
Now, if you are talking about novices (who possibly should only train three times per week), once a higher level of fitness is reached, it will always be beneficial for him/her to increase his/her work load. I think this could be proven far more readily than the alternative hypothesis, that training three times a week yields greater or equal benefits than training 4 or more days a week in trained runners. This, actually, would be a very easy experiment. Thing is, it's already common knowledge that an increase in exercise causes adaptation.
Though I don’t know that you’ve acknowledged it, in advocating 3 days per week of training as optimal you would, necessarily, be suggesting this to runners in the tail end of the "recoverability" distribution. Those of us in the middle already know we can handle and thrive on daily or near-daily running. We’ve all had to cut back due to busy-life factors, and guess what, we find we lose fitness. Your idea of 'do less, get more' has been shown wrong by every individual who has ever progressed from three runs per week to three plus and found they gained fitness. (Yes, I know confounding variables such as overall time training would have to be controlled for.)