Try These Fun and Free HIIT Workouts for an Effective At-Home Workout

HIIT (high intensity interval training) has gotten quite popular over the past decade. Gym-loving celebs always tout the method as one of the more efficient ways to improve your fitness, and science says they ain't wrong.

The boom began in the early 2010s, when several studies revealed that shorter workouts that alternated intense bouts of anaerobic exercise (like a sprint) with recovery periods could improve cardiovascular health just as much as—if not better than—moderate, steady-state style workouts (like a long jog). This meant that we didn't have to spend an hour on the elliptical to get in the benefits of cardio such as improved blood flow, lower blood sugar, less chronic inflammation, and feeling great in our own skin.

However, most of the HIIT workouts you'll find on YouTube won't actually be high intensity interval training at all—and honestly, that actually might be a good thing. Because once you understand how intense HIIT is, you may not want to put it on your workout schedule five times a week.

"True HIIT is very much the standard for pushing your upper training limits," says Allison Tenney, CSCS, a fitness coach based in Austin, TX. It's not just about "getting your heart rate up" as some influencers say; it means that when you're in the middle of those work intervals you are busting your butt to hit 85% of your max heart rate, according to Tenney. Frequently going all-out could lead to extreme soreness, injury, fatigue and overall discouragement. That's why some researchers claim that you should only do up to 30-40 minutes of "true HIIT" a week if you like to ramp things up.

But if you don't, no worries. "Not everyone needs to push those absolute limits to make progress," says Tenney. When it comes to getting results, its about choosing workouts that fit your schedule and that you enjoy, she adds.

And that's exactly what I love about these HIIT-like interval workouts below. They may not all push you to the max, but they are quick, fun, and inspiring. Do one according to your fitness level and observe how badass you feel.