Most of us are creatures of habit. We fall into a workout routine and we keep doing it throughout much of our adult life. We’re not fans of long, monotonous workouts because our lives are busy enough without spending 3 hours at the gym. At least mine is.

Still, it’s impossible to go to a gym that’s not packed with people spending hours at a time on the various treadmills and elliptical machines. Yet most of them aren’t there because they enjoy it. They’re there because they think it’s the most efficient way to burn fat and lose weight.

But here’s the thing: they’re wrong.

Just because the cardio machines may tell you you’re staying in the “fat burning zone” when you’re running at 5.5 mph for 60 minutes, the truth is you’re burning less calories overall than if you worked harder for a shorter amount of time.

Yes, it’s true, you can actually burn more fat and calories when you work out for less time instead of more.
With high intensity interval training, you’ll burn calories more efficiently than you would running for hours.

So what is HIIT?
High intensity interval training (HIIT) is an advanced form of interval training and an exercise strategy alternating periods of short, intense anaerobic exercise with less intense recovery periods.

In plain English, that basically means you’ll be working as hard as humanly possible for a short amount of time, resting, then working hard again. An entire HIIT session usually only lasts for about 10 to 20 minutes.

And if you hadn’t already guessed, every single one of the 12 Minute Athlete workouts is based on the principles of HIIT.

So, for example, a sample HIIT workout might consist of 18 rounds of 10 and 30 seconds (where 10 seconds is the resting period, and 30 seconds is the work period), and include the following exercises:

1. Burpees
2. Push ups
3. High knees w/ jump rope
4. Pull ups
5. Jump lunges
6. Knee raises

In this workout, you’d end up doing three rounds of all those exercises, for a total of just 12 minutes of working out.

The only trick to HIIT? You have to work as hard as you possibly can during the work periods, or you won’t get the results you’re looking for.

HIIT is just one of the coolest, most ridiculously awesome form of exercise there is. Here are 10 reasons to love HIIT:

1. Efficiency
You’ve probably realized this already, but HIIT is one of the most efficient forms of exercise you can do. That makes it perfect for:

Busy people
Lazy people
Anyone who wants to get in better shape but doesn’t want to spend hours doing it

In fact, research shows you can make more progress in just 15 minutes of HIIT than you can running for an entire hour.

2. Burn more fat
Looking to lose some extra body fat? HIIT can take care of this faster than any other form of exercise. The effects of all that hard work from HIIT actually kick your body’s repair cycle into hyperdrive mode,”meaning you actually continue to burn fat in the 24 hours after HIIT, not just during your workout.

3. Burn more calories
Just 10 minutes of HIIT can burn more calories than a half an hour on the treadmill. Plus, just as your body burns fat for 24-48 hours after interval training, you’ll also burn more calories during the time post HIIT as well.

4. Get a healthier heart
If you’re working hard enough during HIIT, you should actually feel like your heart is trying to jump out of your chest because it’s beating so hard (the technical term for this is called the anaerobic zone).

But working this hard has its pluses, including being crazy good for your heart. In one 2006 study, researchers found that after eight weeks of doing HIIT workouts, subjects could bicycle twice as long as they could before the study while maintaining the same pace. Plus, it’ll keep your ticker running smoothly well into old age.

5. No equipment necessary
One of the coolest things about HIIT is that you can still get a kick-ass workout even if you have absolutely zero equipment. That means even if you don’t have access to a gym, don’t have a kettlebell or any other equipment at home, or if you travel a lot, you can still do HIIT. Sprints, burpees, high knees, air squats, there are so many bodyweight possibilities for HIIT!

6. Lose fat, not muscle
Anyone who has been on a diet knows it’s nearly impossible not to lose muscle mass along with fat when you’re cutting calories. But while steady-state cardio seems to encourage muscle loss, studies show that both HIIT and weight training preserve muscle mass while still ridding the body of excess fat. And since muscles are way sexier than no muscles, this is pretty awesome if you ask me.

7. Increase your metabolism
A faster metabolism means that you can eat more and your body will still burn it off (sweet!). And HIIT will give that to you, studies show that HIIT stimulates production of your Human Growth Hormone (HGH) by up to 450 percent during the 24 hours after you finish HIIT.

8. Don’t get bored
One of my biggest complaints of long, steady exercise is that no matter what awesome podcast or pumped up music I’m listening to, I eventually get bored out of my mind from working at the same pace for a long period of time. But even I find it hard to get bored with HIIT workouts. Since they’re constantly changing and always forcing you to work as hard as possible, the workouts are over before you know it, leaving absolutely no time for boredom.
(Hint: if you do tend to get bored during HIIT workouts, it’s time to amp up your intensity level, it’s nearly impossible to get bored when you’re working so hard you think your muscles are going to explode.)

9. 100% portable
Since it’s such a simple concept, go at maximum effort for a short period of time followed by a recovery period and repeat, you can adapt HIIT to whatever time and space constraints you have. That means that even if you’re in a tiny apartment, in the middle of the woods or on a rooftop in Mexico, you’ll never have any real excuse not to do HIIT.

10. Push your limits
HIIT forces you to work harder than you ever thought possible. It gives you the confidence you never knew you needed. It makes you stronger and fitter than ever before. HIIT pushes your limits until you feel like you can really, truly conquer the world.

So go work your butt off and prove to yourself what a badass you really are. You can do it. I know you can.

12 Minute Athlete