Doing a Micro Workout Can Boost Fat Metabolism By 43%—Here's How to Do It
No time? No problem. Science says you can get fit just by slipping in tiny exercise “snacks.”
Turns out, there might be another solution for staying healthy when it feels like you don't have time to exercise. The evidence for short bursts of activity has been mounting for some time. (Remember the 7-minute workout?) But now there's research showing that even really small sessions can have bona fide benefits. They're called exercise snacks. "And they're somewhere between that short walk to the water cooler in pre-pandemic times and high-intensity interval training," says Scott Lear, Ph.D., the Pfizer/Heart and Stroke Foundation Chair in Cardiovascular Prevention Research at St. Paul's Hospital in Vancouver. Think: challenging enough to jack up your heart rate, but only a minute or less at a time—such as 20 seconds of squat jumps, stair climbing, burpees or a fast 60-second run down your block.
These short-and-sweet exercise snacks help build cardiorespiratory fitness, a major indicator of overall health. "Increasing your cardiorespiratory fitness can lower your risk of type 2 diabetes and heart disease," says Martin Gibala, Ph.D., a professor of kinesiology at McMaster University in Ontario. One study Gibala was involved in, published in the European Journal of Applied Physiology, had inactive young adults do 20-second bike "sprint snacks" in which they pedaled as fast as they could. Participants repeated these mini workouts three times a day, each separated by one to four hours of rest. After six weeks, their cardiorespiratory fitness improved by 9%—similar to the 13% increase a second group got by doing the same sprints within longer 10-minute cycling sessions. Other research published in Medicine & Science in Sports & Exercise found that sedentary but healthy women improved their cardiorespiratory fitness by doing just 20 seconds of vigorous stair climbing three times a day for three weeks. "The precise reasons why exercise snacks work has yet to be determined, but they may improve the heart's pumping capacity and ability to transport oxygen throughout the body," says Gibala. They also appear to improve markers of insulin sensitivity and lower triglycerides.
Current exercise guidelines call for at least 150 minutes of moderate-intensity exercise or 75 minutes of vigorous exercise a week (or a combination of the two), which is a far cry from what you'd get from an exercise snack. But doing a few micro workouts can be a good alternative for those days you can't fit in your regular routine. "The message now is anything is better than nothing, and every little bit counts," says Gibala.
No matter your fitness level, exercise snacks are an option for everyone. While inactive people stand to gain the most from them, Gibala says that even gym-going folks with desk jobs can reap the rewards. "Structured daily exercise doesn't negate the harmful effects of sitting for much of the day," he explains. "So these snacks can help break up sedentary periods."
Preliminary research suggests that among people who typically sit for eight hours per day, those who completed five 4-second cycling sprints every hour during the workday (for a total of 160 seconds of exercise) had 31% lower triglyceride levels and 43% higher body-fat metabolism the next day. How's that for a satisfying snack?
This article first appeared in EatingWell, September 2021.