Football is a funny sport in that it asks some of the largest people on the planet to be in incredible shape.

Offensive and defensive linemen, for example, are often over 300 pounds, but are forced to run sprints alongside their teammates.

On Wednesday, Georgia coach Kirby Smart told 247Sports that he’s been disappointed in what he’s seen from the Bulldogs’ defensive line in terms of conditioning, adding that he wants them to be able to stay on the field longer this fall:

“I think all those guys can improve their conditioning,” Smart said. “The world we live in, with the fast-ball and the way we practice it and work on it, those guys who are 300 pounds, they can’t play sometimes more than five, six, or seven plays. I’m not happy with them at all on that.”

Smart said it’s a constant battle to make sure the big guys are ready to play a full game, as it’s hard to keep them in top shape:

“I don’t ever think we are conditioned enough at defensive line,” Smart said. “I’ll believe that when a guy can go out there and play like a DB and play seven consecutive plays and strain his gut and be as effective on the seventh as he was on the first.”

The Bulldogs open the 2017 season on Saturday, Sept. 2, against Appalachian State. Whether the defensive linemen are ready to play a full game by then or not remains to be seen, but it won’t be for a lack of effort on Smart’s part.