Megan Roup, who's been the trainer to Dakota Johnson, Miranda Kerr, Molly Sims, Elsa Hosk and Whitney Port, has developed a series of exercises that can be done in under 10 minutes. (Photo: Courtesy ...

We get it: Some days, you literally only have 10 minutes to exercise. So that means it’s either a 10-minute workout or nothing at all. But some people question whether they should even bother to ...