HIIT is a training method that alternates low- to moderate-intensity intervals with high-intensity intervals. The workouts consist of short, but intense, bursts of exercise with less intense exercise in between. The idea can be applied to most exercises, such as running or even squatting.
Interval training is considered to be more effective because the intensity allows your body to increase both its aerobic and anaerobic endurance, while burning an optimal amount of fat. HIIT is known for getting your heart pumping and metabolism burning. And the best part? You can squeeze in a HIIT workout in less than 20 minutes!
According to an article by The New York Times, past studies have shown that HIIT training "may improve aerobic fitness up to 10 times as much as moderate endurance training." Although studies are still being conducted, Martin Gibala, the chairman of the Department of Kinesiology at McMaster University and senior author of the study, said "'it would appear that there is something important, even essential, about the pulsative nature' of on-off HIIT training if you wish to reap sustained physiological improvements."
Of course, those benefits don't come without a few precautions as well. Steve Edwards, vice president of fitness and nutrition at Beachbody, said that some high-intensity workouts, such as P90X, are not intended for beginning exercisers.
"These were always meant to be 'graduate programs' from some of our other workouts," he told ABC News. "Our target audience may have been deconditioned when they started with us, but for P90X, we see them as someone who has been dedicated to another program for awhile and aspires to go further."
Edwards also mentioned that exercisers should "check with their doctors and not overdo it" before starting such workout programs, and the doctors agree.
Dr. Stephen Fealy, an orthopedic surgeon at the Hospital for Special Surgery in New York, told ABC News that he started seeing a spike in HIIT-related injuries over the recent years, mostly involving muscle sprains and tendon strains — particularly of the calf, chest and shoulder — which is a result of overusing explosive movements and heavy weights.
"I think these programs are quite good," Dr. Fealy said. "But if someone goes from couch to full throttle without any preparation, there's a good chance they're going to get hurt."
Moral of the story? If you're just starting out, high-intensity programs might not be right for you just yet. But, if you're already a workout warrior and looking to up your game, perhaps HIIT is just what you need.
Want to give it a try? Here a few of the most intense workouts we could find!
And you'll see personalized content just for you whenever you click the My Feed .
SheKnows is making some changes!