The Breakfast Club star, 42, admits she never imagined she'd become one of the celebrities lacing up running shoes - and she's surprised she has the stamina for it.
She tells Bust magazine, "I took up running this past year. I've never been a runner in my entire life. I didn't even think that I could run, and I discovered at age 41 that I actually can run.
"So I want to continue that trend and be as great as I can be."