This 28-day challenge will turn you into a person who works out 15 minutes a day, four or 5 times a week. There is a lot of pressure to be healthy , but if you’ve never really worked out before or you’re trying to get back on the fitness horse, it can be confusing or intimidating to know where to actually begin. That’s why we put together a realistic, not-super-intimidating exercise plan made up of bodyweight and cardio workouts you can do basically anywhere in 15 minutes.