HIIT workouts, or high-intensity interval training, are popular among fitness fanatics — they're short, effective and leave you sweaty. But are they really better than a 60-minute run?
In the widely reported study earlier this year (with the irresistible 1-minute exercise headline), researchers from McMaster University found that a 10-minute workout could be just as effective as a 45-minute one.
TODAY's Sheinelle Jones was up for the challenge: she tested the effectiveness of fast, or HIIT, workouts for three weeks.
"If you're willing and able to go hard, it would appear that you can get away with a surprisingly small dose of exercise and still boost your fitness," said Martin Gibala, Ph.D, professor and chair of the department of kinesiology at McMaster University and lead researcher of the study.
Gibala created a program for Sheinelle to try. Her goal? To boost her cardiovascular fitness and increase the oxygen capacity in her lungs. She performed 10-minute workouts, three times a week. One minute of each workout would be high intensity, broken into 20-second bursts.
At the end of three weeks, her results were impressive: Sheinelle increased her V02 max (maximal aerobic capacity) from 26 to 27.5, which could be equivalent to a one inch body change according to Gibala.
Could this work plan work for you? According to Dr. Jordan Metzl, it's a routine anyone could follow.
In the study Gibala led earlier this year, researchers split men in their mid-to-late 20s into three groups:
- One group didn’t exercise at all
- One group had workouts where they biked for 45 minutes at a steady pace
- The last group did 10-minute workouts consisting of a warm-up and three 20-second sprints on a bike, followed by two minutes of slow pedaling.
It's important to note that none of these groups worked out for only one minute — though the 10-minute workout was the shortest.
Three months into the new routines, researchers performed a series of tests on the participants. And what they found was fascinating.
“We looked at aerobic fitness (how well the lungs used oxygen), insulin sensitivity (the ability of your body to process blood sugar — a risk factor for Type 2 diabetes), and muscle content (how efficiently your muscles use oxygen to produce energy),” said Gibala. “And after three months, the two groups of exercisers saw the exact same improvements.”
In other words, the group that worked out for 45 minutes wasn’t any more fit than the group that exercised for 10 minutes.
But before you replace all of your workouts with super-abbreviated versions, there are a few caveats.
“While we found that both groups had a slight but significant reductions in body fat percentages, we didn’t look at any other factors like whether both kinds of workouts had the same impact on stress levels or mood,” says Gibala. “People work out for many reasons and there’s no one-size-fits-all approach to workouts, so this might not be the answer for everyone.”
Sheinelle noted that the 10-minute workout didn't allow her to clear her mind the way a longer run or bike ride might.
The other warning: While one minute of high-intensity activity (in the case, broken up into intense 20-second intervals) sounds easy, it isn’t.
“A lot of people don’t understand that the people in these studies on high-intensity intervals are pushing themselves incredibly hard,” said Cedric Bryant, Ph.D, chief science officer for the American Council on Exercise. “To create similar results on your own, you have to make sure you are operating at peak intensity for those 20-second intervals.”
If that sounds unpleasant, it’s because it is.
“One of the concerns about these kinds of workouts is that people might find them too challenging, meaning they won’t stick with them in the long-term,” said Bryant. “And the best benefits from exercise come from doing it for an extended period of time and really making it part of your lifestyle.”
A better approach is that instead of replacing all of your workouts with this short-but-intense version, mix it up.
“Lack of time is a big reason people say they don’t exercise consistently,” says Bryant. “This way you have an option for days you are really busy while doing other kinds of workouts when you have a little more time.”
While the researchers looked at cycling, other forms of cardio like swimming and running would work just as well. And don’t worry women: Gibala expects that both sexes would respond to this kind of intense interval training.