
As for doing something like rowing a flat out 2k and only a 2k each and every day, a sample size of 1 means roughly squat to the general population. Offhand, I'd say the odds are that some other training regimen would serve most people better. But I doubt that the guy doing it will give up what seems to be working. There's usually a 'virgin in the volcano' aspect to athletes and self-authored training plans: you throw the virgin into the volcano every year to keep it from erupting because you always have and it's 'worked' so far. Then one day the volcano does what it will. Generally the conclusion will be that the sacrificial ritual was performed wrong (she wasn't a virgin!), not that the rite never had anything to do with the outcomes you were getting....