I must have watched that video a dozen times. 
His body went into shock when he started running. It was that alien to the very concept of running. He did that to his body, chugging on them same beers and burgers for years, then expected peak performance from his legs. His body looked him dead in the eye and proclaimed "nigga please!"
Don't be young and out of shape.
Because when you get older, you are likely going to be more out of shape.
Because when you get older, you are likely going to be more out of shape.