I agree and I think of it another way. The day to day life and focus of many modern day olympians / world champions was probably close to the norm for many of t

I agree and I think of it another way. The day to day life and focus of many modern day olympians / world champions was probably close to the norm for many of the fighter-class. People training day in day out to hone their skills and fitness, putting their lives on the line for glory and survival. Sure we eat better and train smarter but most of us no longer dedicate ourselves to a singular purpose that involves our bodies so the realities of that are so foreign to us that the notion of marching a marathon carrying 40kg is seen as superhuman rather than the bare minimum.