There’s a growing trend in the workout world called high-intensity interval training (HIIT), also referred to as speed interval training. Or, as some people think of it, running like you’re being chased by a zombie, pausing to catch your breath, and then booking it again. Whew! And it’s a concept that attracts firm believers.
Michael Mosley, MD, a medical journalist in Britain, recently suggested that it’s possible to improve fitness with just three minutes of exercise a week using HIIT. To prove it, he followed a HIIT routine that involved cycling on a stationary bike as hard as he could for 20 seconds three times, taking a few minutes to catch his breath in between the 20-second intervals. The result? After doing it three times a week for four weeks, his insulin sensitivity improved by 24 percent.
Certainly sounds impressive—who wouldn’t like the idea of getting fit with less effort?—but could it work for you? We asked our experts to weigh in on the HIIT trend:
Does high-intensity interval training work?
"I’m a big fan of interval training, but the total bout of interval training needs to be within at least a 15- to 20-minute period to get maximum cardio and calorie benefits. You’re not going to burn a lot of calories in a 3-minute workout; no matter how hard you train, you’re only going to burn about 20 calories a minute.” –Wayne L. Westcott, PhD, Prevention fitness advisor and fitness research director at Quincy College
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“I think it’s highly effective and a great cross training workout. But in terms of overall health and cardiovascular endurance, there’s nothing better than working out for 30 minutes three to four times a week. HIIT is a great thing to incorporate into your workout—the whole concept of burst and then recovery cycle for aerobic exercise is great—and it can help improve cardiovascular health faster according to recent studies.” –Chris Freytag, Prevention contributing editor, trainer, and author of Two Week Total Body Turnaround
“I’ve used interval training in my step classes for years. Push hard for a minute or less and then keep going but at a much lower level of intensity, until it’s time to crank it up again.” –Kathy Kaehler, celebrity fitness trainer, author of Mom Energy
“I’m a big advocate for HIIT training. My mantra is that doing a little bit is better than nothing at all. If you’re doing 10 minutes of a hard-core workout, you’re going to burn more calories than doing a 20-minute workout at a slower pace.” –Jennifer Cohen, founder and author of No Gym Required
How long should you do HIIT training for?
“I think this type of workout is best three times a week if you do it properly. You need every other day to recover.” –Kathy Kaehler
“Try to do HIIT twice a week. I use it more for conditioning and to shock my body into something I’m not used to doing. It’s great to do it as part of your workout, but not your only form of exercise because it doesn’t train you for overall wellness.” –Jennifer Cohen
“I don’t know if there’s any exact perfect time. Continuous aerobic training is usually 20 minutes or more. I like the Tabata method of training that involves 20 seconds of high intensity and 10 seconds of recovery. Do eight cycles of 20 seconds hard, 10 seconds rest, in a row. That appeals to me because I think 'I can do anything for 20 seconds.'” –Chris Freytag
Is HIIT safe for beginners?
"There is much more deficit than benefit to these types of programs for beginners. If they did do it, I certainly would want them to take a long warm up and a long cool down before doing something that intense." –Wayne L. Westcott
“I wouldn’t recommend this type of training to a beginner—it’s a perfect way to turn them off. This is more effective and welcoming for someone who is already involved in a program.” –Kathy Kaehler
“A beginner is more likely to get injured because their technique gets compromised if they don’t know what they’re doing.” –Jennifer Cohen
“I think it can be adapted for anyone. It’s great for your basic fitness enthusiasts and recreational exercisers. Try some high-intensity training to burn more calories in less time and get the heart health benefits. For your average fitness enthusiast, I suggest working to the point where you’re breathing so hard you can’t talk, and then pull it back to where you can still breathe.” –Chris Freytag