Fact: “The best time to exercise is anytime you can do it,” says Samantha B. Cassetty, M.S., R.D., nutrition director at the Good Housekeeping Research Institute. You get the same payoffs and burn essentially the same number of calories whenever you work out. What’s important is doing it regularly. Some studies have shown that ﬁrst-thing-in-the-morning exercisers are more likely to stick with a regimen than those who start late in the day, but that’s because it’s probably easier to postpone an evening workout until tomorrow. So whether you have more time or energy in the morning, afternoon, or at night, the important thing is that you do it.
Myth: Your body won’t burn fat unless you exercise for more than 20 minutes
Fact: You burn fat around the clock, whether you’re exercising or not. For the biggest calorie burn, exercise as hard as you comfortably can (you should still be able to carry on a conversation) for as long as you can.