CoachB wrote:
I had a lot of the same concerns with his explanation of how the fiber types develop. I mean, why wouldn’t daily 2 hour runs also develop those IIa fibers if all systems work at all paces?
Don’t get me wrong, cv pace is super effective, but I just don’t know how you’d back up hos claims without pre training / post training muscle biopsies.
In his podcasts he mentions your concerns. Race pace work can develop the athlete quickly but has a high risk-high reward in terms of how quickly the athlete can garner adaptions before he is good to go again. He posits that most athletes also run their easy days too fast. That would mean that suddenly these workouts become very, very high risk for a high reward.
He specifically mentioned this when talking about 3k-5k effort intervals. He also mentioned how threshold running develops the intermediate fibers and the lactate threshold with low risk-moderate rewards. He mentions a study about how the athletes lactate threshold improved with both VO2 max, threshold, and CV. However, VO2 saw the least improvement, with CV garnering the most. This was over a 4 week period conducted with runners in Australia. All three paces will get the job done, but VO2 is hard to recover from which means that the adaptations take longer to occur. Threshold running is good, but it takes a longer period for the athlete to develop through it. CV is a middle ground where the intensity helps with further development than threshold, but also is easy enough to bounce back from it quick enough to do more of it so you can keep compiling fitness. I would assume super long runs like you said would accomplish all of this too but extremely slowly.
He claims his ex-wife burned his files on the Australian study (I am not kidding), so I don’t know what he is really referencing. But that’s where he claims to get his info from.
All of these suggestions WORK. The reason why he is a proponent of CV is because it isn’t sexy and just gets the job done. It’s easy to bounce back from it so you can do more and more, but it is hard enough to rapidly develop the athlete. Again, his claims not mine.