While testing high mileage on developing bodies is highly controversial in regards to medical science, I think it’s worth noting that some of the greatest ultra athletes of all time, such as Anton Krupicka, who ran 100mpw since aged 13, completing his first marathon aged 12, have been running mileage as high as this since their early teenage years. I’m interested in whether people think that these athletes are at a physiological predisposition to the normal person, or if the mileage takes place at a low intensity, anyone can manage this? Open to any suggestions?