If you’re still wondering how to lose weight fast and keep your heart and lungs in the best shape possible, the next best training protocol to add is High Intensity Interval Training (or HIIT). 

HIIT burns a lot of calories in a short amount of time, which is great for people who don’t have a ton of time to exercise. Unlike regular steady-state cardio (like long jogs or hours on a treadmill), however, HIIT never really enters the “fat burning zone.” Sounds like a fail, right? 

WRONG!! In fact, what happens with traditional long, cardio is you get into that fat burning zone, but you have to stay there for 30 minutes. Then the zone -- and the fat burning -- disappears the second you stop. 

Like, immediately. 

Plus, when you go back, your body will have adapted, and you’ll find you need to work longer to burn the same number of calories. Not good! 

HIIT, on the other hand, forces your heart rate to go up and down in short bursts of activity. This leads to an increased metabolic rate over a 24-hour period, keeping you burning more energy longer. In this state, you’re using more energy even at rest, which keeps you scorching calories around the clock. 

Movements like sprints, hill sprints, squat jumps, or any other type of exercise you can perform at max effort burns a lot of calories, but also builds a lot of muscle. You can’t turn fat into muscle, but if you can burn some fat away and build some muscle in the process, you’ll see changes a lot sooner. 

Perform some variation of HIIT 3-4 times per week with a lot of walking on your off days, and you’ll start losing weight fast.

To get the most out of HIIT training, consider doing something called “burst training.” 

Bursting really means doing short bursts of incredibly high-intensity exercise. 

For example: 

After a four-minute warm up, do a sprint -- full out, as fast as you can (as if you’re being chased by a lion) -- for 20 seconds. Then rest for a minute and 40 seconds. Then do it again. Then again. Then one more time. And that’s it. 

That’s the whole workout. I know it doesn’t sound like much, but the energetic output is massive. Your heart and lungs will be trained almost as well as if you were going for distance. Your blood pressure will adapt down. And your metabolism will be primed to burn around the clock. This is your body’s way of not knowing if you’re going to be chased again, so it stays in a state of readiness. That means keeping a supply of fuel free-floating in the system, and that means releasing stored fat for energy. 

Not a bad deal for 12 minutes of exercise.