When it comes to working out, a fairly standard recommendation is to do 20-60 minutes of continuous moderate-to-vigorous intensity exercise three days a week. That’s according to the American College of Sports Medicine, so we’ll take it. And it’s not a drastic time commitment, especially when you consider the many benefits — looking and feeling better, plus warding off obesity-related maladies, including diabetes, hypertension and cardiovascular disease.
However, one of the most common reasons people give for not working out is that they simply don’t have the time. Between work, family and a social life, it can feel like there simply aren’t enough hours in the day to fit in the time to get fit.
But can you spare 10 minutes?
A recent research study published in Clinical Physiology and Functional Imaging compared the fat metabolism between a single 30-minute bout of exercise and three 10-minute bouts at the same intensity and found that the repetition of 10 minutes of moderate exercise can contribute to greater fat oxidation.
OK, I can add. Working out 10 minutes a day three times a day still means you’re devoting 30 minutes to exercising, but hear me out.
As someone who spends the majority of her eight-hour-plus workday sitting at a desk in front of a computer screen, I like the idea that I could get up and take a 10-minute power walk or climb the stairwell a few times (switching out heels for sneakers, of course) and potentially see greater fat-burning benefits than if I dragged my butt to the gym after a long day at the office. Yes, that’s three 10-minute breaks in a given workday, but on top of improving my physical well-being, I get the mental benefits of exercise — improved mood, clearer head, etc., which should only help my focus and productivity.
So, if you’re still with me, let’s take a closer look at what researchers found out about a shorter workout.
The study took nine healthy males and put them through three trials in random order separated by at least seven days:
1. A single 30-minute, moderate-intensity bout of exercise on a stationary bike after which the subjects rested on a comfortable chair for 180 minutes while their metabolic responses during the recovery period were measured.
2. Three 10-minute, moderate-intensity bouts on a stationary bike (same intensity as single trial) separated by 10-minute resting periods, and followed by a 180-minute resting period on the same chair.
3. Complete rest (yup, same comfy chair).
The subjects were instructed to refrain from severe physical activity during the 48 hours preceding each trial, and they also consumed the same foods and portions for dinner on the night before, and were then instructed to fast until after the trial the next morning.
Researchers found that the respiratory exchange ratio (RER) during the recovery period was consistently lower after the three 10-minute bouts of exercise than after the single 30-minute bout of continuous exercise, and remained consistently lower throughout the 180-minute recovery period. And the average percentage fat contribution throughout the recovery period was approximately 15 percent greater in the repeated trial than in the single workout and complete rest trials.
In other words, the results indicated that the repetition of three 10-minute bouts of exercise burned more fat during the post-exercise period. And the benefits didn’t end there.
Blood glucose and lactate concentrations immediately post-exercise were significantly higher in the single trial than in the repeated trial throughout the 180-minute rest period. Heightened levels of these metabolites are generally considered to be a bad thing, especially among untrained individuals, the elderly and people with diabetes.
Finally, although both groups worked out for a total of 30 minutes at the same intensity, those in the repeated trial reported less perceived exertion, i.e., they didn’t feel as tired. That’s more great news for people who don’t like to work out.
So, for all of you out there who say you don’t have the time to hit the gym for 30 minutes, why not try to sneak in a few shorter workouts throughout the day instead?
 Goto K et al. A single versus multiple bouts of moderate-intensity exercise for fat metabolism. Clin Physiol Funct Imaging. 2011;31;215–20.