This may help a little,
I have a friend who is coached by one of the “crew” members, and he does a lot of stuff like this, especially in gpp. He showed me the stuff he was given to do over thanksgiving break and the volume was huge and the intensity looked much to high… none the less the program he runs for has really squandered great talent, many 47 high school guys have gone in and never come near that again. I have an idea as to why the length and intensity of these runs is what it is but I feel I am not at liberty to discuss that on these boards