Sunderland boss Paolo di Canio is driving his players hard in preseason.
Di Canio is putting his troops through intensive double sessions to get them in tip-top condition for the new season.
He said: "It's important for the squad to improve together, to bond and to learn how to suffer together.
"With hard work now, we can lay foundations for a fantastic season.
"I want my players to build a good athleticism, strength, power and resistance.
"I want them to be able to adapt to fatigue and go beyond their possibilities, otherwise it's difficult to become a better footballer."