Justin Foster might get the urge to pick up the pace in the grocery store and whisk from aisle to aisle, but his body will force him to slow down. The chest pains will hit. He’ll have difficulty breathing. And before he has purchased his items, Foster either will have to find a seat or leave altogether, unable to complete what was once a simple task.

A little more than a year ago, Foster was a star defensive end at Clemson, terrorizing LSU in the College Football Playoff championship game. And yet 10 months after he tested positive for the coronavirus, menial activities have the potential to level him.

“If you see me walking around, you would think everything is normal. But most of the time, I will be short of breath,” Foster, who has asthma, said in a telephone interview. “I won’t tell anyone. I don’t really try to draw attention or complain about it. I try to deal with it.”