The laundry bin’s overflowing; the phone’s buzzing; and we still have yet to finish that project due first thing tomorrow morning. Before adding a long, slow jog around the park to that to-do list, consider this:
According to new research from Liverpool John Moores University and the University of Birmingham, high-intensity interval training can be a time-saving alternative to endurance training. So even though HIIT takes half the time, it can result in the same health benefits that we get from endurance activities .
What’s the Deal?
Researchers recruited 16 young sedentary males with an average age of 21 to compare the effects of endurance training and sprint interval training. Some of the participants did six weeks of endurance training, (40 to 60 minutes of cycling five times per week). The rest did high-intensity interval training, (four to six repeated 30-second “all-out” sprints on bikes interspersed with 4.5 minutes of low-intensity cycling, three times per week). In the next phase of the study, researchers took muscle biopsies before and after participants completed 60 minutes of cycling.
It turns out that both forms of exercise — five hours of endurance training and just 90 minutes of HIIT — helped reduce aortic stiffness (which affects how quickly blood travels through the arteries) and increase whole body insulin sensitivity (how efficient the body is at processing glucose). That’s important because it means HIIT and endurance training were equally effective at helping decrease the risk of heart disease, hypertension, and diabetes.
Is It Legit?
Looks like it. This study adds to a growing body of research suggesting that, in adults and kids, HIIT is a more time-efficient way to see the same health effects we get from endurance training  . Specifically, research suggests HIIT can increase skeletal muscle oxidative capacity (how efficiently muscles use oxygen) and improve exercise performance  . We can even reap these benefits from low-volume high-intensity interval training (HIIT), which involves 15- to 60-second bursts of high-intensity cycling interspersed with two to four minute intervals of low-intensity cycling.
There’s also some evidence that people are more likely to stick to HIIT training routines than endurance regimens . That’s possibly because HIIT takes a whole lot less time, and packed schedules are one of the main reasons why adults don’t exercise. Even better news? Scientists say HIIT is appropriate for people of all ages and fitness levels (start sprinting, Gramps!) .
On the flip side, of course, this research isn’t implying that long-distance runners can say bye-bye to longer runs. There’s a time and a place for mileage and marathoners and other endurance athletes will still have to log some distance in preparation for race (or game) day. It’s also important to note that intense sprint-based exercises can deplete the body’s energy stores, especially glycogen . So it’s worth mixing it up with some less intense cardio workouts so that the body can refuel.
No matter who we are, one of the most important parts of establishing an exercise routine is finding something enjoyable and maintainable. So for those who look forward to a 45-minute treadmill run at the same pace, it’s not necessary to switch to intervals immediately. But it is good to know that even when we’re in a huge rush (aka always), there’s still time to practice good health habits.
Have you tried high-intensity interval training? What’s your favorite HIIT workout? Let us know in the comments below or tweet the author @ShanaDLebowitz.