The whole point is you don't have to kill yourself every training session. Training must be fun and enjoyable. He said some guys go all in 3 days in a week. Then the next day wakes up sore and unmotivated. You don't need to run 5 miles everyday. Instead you could run 2-3 miles everyday and repeat it whole year. He says hard training causes injury. In the end your overall training time will surpass hard trainers. You've trained more without damaging your body and it's good for your health, career in the long run.