Study Finds Just a Few Minutes of HIIT Might Be as Effective as Longer Moderate-Intensity Workouts

If time constraints keep you from working out, you’re in luck. A group of Australian researchers recently found that just a few minutes of HIIT (high-intensity interval training) might be just as beneficial for the body on a cellular level as a full 30 minutes of moderate exercise.

The small study, published in the American Journal of Physiology, recruited eight young adult volunteers and recorded their cellular response to exercise. While most people gauge how effective their workouts are by the number they see on the scale, the cells in your body tell a better story.

The scientists looked at mitochondria, in particular, which are responsible for producing energy. As we age, the production of energy made via mitochondria slows down, which is why you might feel like you have less energy now than when you were in your early twenties.

The study examined the changes in mitochondria after the participants did three different kinds of exercise:

• Moderate exercise for 30 minutes.
• HIIT or high-intensity interval training. In this study the participants performed five four-minute cycling sessions at maximum effort, followed by one minute of rest.
• Sprints. In this study, the participants completed four 30-second cycling sessions followed by four and a half minutes of recovery time.

HIIT produced a similar mitochondrial response as longer moderate-intensity workouts

Interestingly, the small study found that just two minutes of HIIT was enough to produce similar cellular responses in the body as 30 minutes of continuous moderate intensity aerobic exercise. While this study only looked at eight individuals, researchers are hopeful this is a sign that shorter, more intense workouts can reap major metabolic benefits.