Sunderland boss Paolo di Canio is determined to improve the fitness base of his players.
Di Canio intends to ensure his players are in tip-top shape when the Premier League season kicks-off on August 17.
He said: "I am not a masochist, but the players will tire in games - it will happen, it will happen often, especially against clubs like Manchester United who keep the ball 70 minutes out of 90.
"You have to run, resist and keep your concentration high.
"You can only do that if you adapt to fatigue, and that means going over your limits.
"Otherwise it is difficult to become a better footballer."