#2 It’s The Fitness Equivalent of Buy One Get One Free
You might not think that it’s possible to squeeze a solid strength-training session and a calorie-torching cardio workout into a quick routine, but you would be wrong, says Metzl. With HIIT, you’re pushing yourself as hard as you can go to accomplish as many reps as possible. That butt busting earns you cardiovascular benefits. By incorporating strength-training exercises into your intervals (as well as cardio moves), you also reap muscle-strengthening benefits, he says.