Female feet in violet sneakers do exercise on a black-turquoise fitness aerobic step. Side view.

The Most Effective, Efficient Exercise in Just 4 Minutes a Day

You probably have a friend who spends hours on elliptical machines reading People Weekly and talking with her on-again/off-again boyfriend. She also swears by her gym’s Tuesday night aerobics class as an excuse to hit the new fro-yo place around the corner, since (according to her) she burns 500 calories in this class. You’re convinced the hot instructor is her only reason for attending class, and that those hours huffing away on treadmills benefit her Kim Kardashian knowledge but not her abs.

Besides, you could never find all those hours to work out in your busy day.

Ditch those useless treadmills and social hour/aerobics classes (admit it: you’re there to chat with your girlfriends as much as exercise) for fast, effective exercise in as little as four minutes a day.

You read that right. Infomercial-speak aside, science backs burst training as the fastest, most effective exercise on the planet.

What is Burst Training?

High-intensity interval training (HIIT), also called burst training, involves short bursts of high-intensity-style exercise for 30 to 60 seconds followed by one-to-two-minute recovery periods. (I will use burst training and HIIT interchangeably throughout this article because the work/rest ratio concept are the same in both.)

You can do burst training practically anywhere. Stuck at a hotel? Find the stairs. See that giant hill at your local park? Run up it.

The key involves full-out maximum speed for up to 60 seconds. Dump the longer-is-better exercise myth: If you can do burst training over a minute at a time, you’re not doing it hard enough. (Literally) step it up. You’ll subsequently slow down to a normal pace to catch your breath, and then repeat.

“The science behind burst training is based on something called the ‘excess post-exercise oxygen consumption’ (EPOC) effect, which is the recovery of one’s metabolic rate back to pre-exercise levels,” says Certified Strength and Conditioning Specialist Jini Cicero. “It is a measure of how much oxygen the body utilizes in the period immediately following a workout or bout of exercise. EPOC directly effects fat oxidation in response to high-intensity exercise.”

In other words, when you burst, your body creates an oxygen debt that it must then repay. This recovery requires energy, which your body utilizes via fat oxidation. Literally, you’re burning fat to meet this demand.

Science Proves Fast Exercise Superior for Fat-Burning

Imagine you could find a way to pack your eight-hour workday into just one hour. It requires more intense work, but you get more done during that one hour than you ever did before. Think of all the time you could spend shopping and hanging out with your partner!

That’s how I want you to view burst training: as a fast, efficient way to get fat-blasting exercise. Sure, it takes more work than watching The View while working an elliptical machine, but burning more fat in less time is a nice trade-off.

Studies indicate that HIIT is superior to cardio. One in the journal Metabolism, for instance, compared a 20-week endurance-training (ET) program to a 15-week burst-training program. The HIIT group showed a ninefold greater fat loss than the ET group.

Numerous other studies demonstrate burst training’s effectiveness for fat loss. One in the Journal of Obesity, for instance, found that burst training forces your muscle to utilize more fat both during and after exercise.

And a study in the Journal of Applied Physiology found that moderately active women burned impressive amounts of fat doing just two weeks of burst training.

You get it: Burst training burns more fat in less time than cardio. And now you’re wondering how exactly burst training provides those amazing results in just minutes a day. Let’s look at five reasons:

1. Burst training helps your body adapt to stress. Just to be clear: all exercise raises cortisol. This stress hormone gets a bad rep, but it can work for or against you depending on what you’re doing. “Cortisol is the Jekyll-and-Hyde hormone because it can be your best friend or worst enemy when it comes to fat loss,” says Dr. Jade Teta. “Long-duration cardiovascular exercise increases cortisol, but never breaches the intensity threshold necessary to get trigger [fat-burning hormones] like human growth hormone (HGH) and testosterone.” (More on HGH in a minute.) Chronically elevated cortisol can lead to muscle breakdown and fat storing.

On the other hand, burst training raises those anabolic (building) hormones like testosterone and HGH, which increases fat burning. Burst training also teaches your body to better handle stress and recover more effectively.

2. Burst training promotes post-workout fat burning. Sure, you’re burning fat while you ride that treadmill, but the lower intensity doesn’t require any metabolic post-exercise repair. Because fat burning and metabolism are not enhanced post-workout, you get limited overall metabolic benefits. Put another way: the more intense your exercise, the bigger metabolic cost you create when you’re done.

“It’s not the workout itself that has the greatest impact on fat burning,” says Cicero. “Rather, it’s the effect of that workout on the rate of calories burned afterward, over the course of the day even into the following day.”

3. Bust training raises human growth hormone. Repeated, intense bursts raise lactic acid, which spikes human growth hormone (HGH). HGH is your “fountain of youth” hormone. It helps you burn more fat, boosts your immune system, increases testosterone levels, and decreases inflammation. Want a one-two punch to increase GH? Get an uninterrupted eight hours of sleep every night and then do burst training three or four times a week.

4. Burst training reduces your risk for chronic diseases. Fat isn’t just an aesthetic issue: it can also contribute to numerous problems like diabetes. HIIT can help reduce your risk for these and other diseases.

One study in the American Journal of Cardiovascular Disease concluded that, compared with endurance training, HIIT was an effective way to control and prevent hypertension.

According to Dr. Mark Hyman, author of The Blood Sugar Solution, 24 million people have diabetes, and half of them don’t even know it. Burst training can provide an effective exercise to ameliorate diabetes. A study in the Journal of Applied Physiology, for instance, showed that for people with type 2 diabetes, burst training can rapidly improve glucose control and improve metabolic health.

Dr. Hyman also estimates 60 million people have pre-diabetes, or insulin resistance that paves the path for full-blown diabetes. A study in the journal BMC Endocrine Disorders showed that exercise could help prevent diabetes in otherwise-sedentary younger males. “The efficacy of a high intensity exercise protocol, involving only [a small amount] of work each week, to substantially improve insulin action in young sedentary subjects is remarkable,” researchers noted.

5. Burst training saves you time. My clients often complain they don’t have hours to spend at the gym or otherwise get in shape. Burst training blows the time excuse out of the water. After all, you’re looking at 30 minutes max, which even the busiest person can schedule (yes, schedule) into their insanely hectic day.

You don’t need expensive equipment, fancy workout clothes, or a gym membership. Some people favor compact, portable machines like the Xiser, but you can get equally effective burst-training results in your mall stairs or park hill. The worst you can say is that people might look at you funny, but that’s a small price to pay to burn fat and get in peak condition.

One last thing: I’ve combined burst training with weight resistance in my 4 x 4 Workout, which you can do in just 15 minutes, three times a week. Talk about effective and efficient: these are serious kick-butt workouts that will leave you lean and toned in time for beach season. My readers can get a FREE 4 x 4 Workout.

Babraj JA, et al. Extremely short duration high intensity interval training substantially improves insulin action in young healthy males. BMC Endocrine Disorders 2009, 9:3.

Boutcher SH. High-intensity intermittent exercise and fat loss. J Obes. 2011;2011:868305. Epub 2010 Nov 24.

Ciolac EG. High-intensity interval training and hypertension: maximizing the benefits of exercise? Am J Cardiovasc Dis. 2012;2(2):102-10. Epub 2012 May 15.

Little JP, et al. Low-volume high-intensity interval training reduces hyperglycemia and increases muscle mitochondrial capacity in patients with type 2 diabetes. J Appl Physiol. 2011 Dec;111(6):1554-60.

Talanian JL, et al. Two weeks of high-intensity aerobic interval training increases the capacity for fat oxidation during exercise in women. J Appl Physiol. 2007 Apr;102(4):1439-47.

Tremblay A, et al. Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism. 1994 Jul;43(7):814-8.