We know all workouts are not created equal. Weight lifting, running, shooting hoops; every exercise has its own benefits and at the end of the day, any of them show your body more love than Netflix in bed. And then there's HIIT.

High Intensity Interval Training workouts are blowing up in popularity for the myriad of benefits they bring in a shorter period of time than the standard gym routine of steady-state cardio (think elliptical) followed with weights.

HIIT involves one exercise at an interval of 20 seconds to a few minutes, alternated with a recovery period of active rest such as jogging in place. This is repeated 10 or more times to build a workout of 15 minutes to an hour.

There are tons of variations of HIIT workouts from bodyweight to kettle-bell to bike, and many gyms even offer classes so you can skip the planning and go straight to sweating. But the one thing I see most when it comes to HIIT workouts is... they aren't HIIT at all. They're just IT.

The most important part of a HIIT workout is that each interval of 20-60 seconds is giving the exercise everything you've got. If you're doing HIIT on a track, you're sprinting. If you're doing HIIT with burpees, by the time your timer's up, you're dropping to the ground in exhaustion, The key to unlocking HIIT's full benefits is truly pushing your endurance levels.

HIIT workouts can burn an additional 15% more calories post-workout. That means if you HIIT it in the am before class, your body is still torching cals while you sit in your lecture. This is because HIIT workouts increase your EPOC, or excess post-exercise oxygen consumption levels. Your body has to work throughout the day to recover from such vigorous exercise.

But this means the exercise really does have to be all out. During the high intensity interval, you should be peaking at 80-95% of your max heart rate. While 30 seconds of crunches are killer for the core, its not going to get you there. Likewise, if you're running at the same pace for 10 minutes, you're most likely not in that max heart rate range.

If you're looking to try a HIIT workout, here's a simple 15 minute full body circuit:

1. High Knees

2. Squat Jumps

3. Mountain Climbers

4. Jumping Lunges

5. Burpees

Perform each exercise on the list for 30 seconds, with 30 seconds of active rest before the next exercise. Active rest is anything short of lying down that will keep your heart rate somewhat elevated such as jogging in place or squatting. Run through the entire circuit 3 times.

The great thing about HIIT workouts like this is that there are modifications for you no matter what your fitness level is. Your first week of trying HIIT, maybe you step your feet out into a plank when you burpee. After a few times, you can work your way to jumping out and eventually add push ups or even single-leg burpees!

No matter what, you're getting a great workout in a short amount of time. You can't half-ass high intensity. If you want to HIIT it, you have to HIIT it hard.