To Lose Weight, Try Less Exercise

A new study shows that sometimes vigorous exercise backfires when trying to shed pounds.

Results from a new study published in the American Journal of Physiology suggests that when it comes to weight loss, 30 minutes a day of exercise is key. Photograph courtesy of Shutterstock.

Anyone who’s tried to lose weight in a healthy and smart way knows exercise is a key component to slimmer waistlines. But anyone who’s tried to lose weight also knows that exercise alone is not the end all, be all.

Of course, we’re not knocking gym time. But at times even the most rigorous exercise regimen can actually lead to the exact opposite of what’s desired: weight gain. New research out of Copenhagen has proved that very notion, with results showing that when it comes to weight loss, less exercise may actually be more.

The study involved 43 young and healthy but overweight men. To test the effects of aerobic exercise on body composition and energy levels, the men were split into three groups: a sedentary control group, a moderate exercise group that worked out for 30 minutes per day each, and a high-exercise group that worked out for 60 minutes a day.

Both exercise groups had to either run or cycle and wear heart monitors all day, so that researchers could track other means of physical activity.

At the end of the 13-week study, researchers found that, not surprisingly, the sedentary group had neither lost nor gained weight. They also found that overall, the two exercise groups experienced a combined body fat reduction of 14 percent.

But what really stumped the researchers was that the two exercise groups showed no significant difference between body compensation and fat reduction at the end of the study, even though one group burned twice as many calories as the other. The men in the high-exercise group lost 20 percent less weight than researchers expected, while the men who exercised moderately performed 80 percent better than expected, losing an average of seven pounds each.

There are, however, some explanations to the findings. One is that the high-exercise group likely could have been burnt out from the vigorous exercise, and thus were more likely to remain sedentary when not exercising. They may have also been inclined to indulge with their diets after a workout.

But why did the men who burned just 300 calories a day from exercise do so well? The study author Mads Rosenkilde told the New York Times that based on what the monitors picked up, it looks like the men were more likely to stay active and move around when not exercising. This resulted in a “bonus effect” that likely led to the increased weight loss. 

Currently, the physical activity guidelines for Americans suggests that adults engage in at least moderately intense exercise for at least 150 minutes per week, and perform 75 minutes of vigorous-intensity exercise per week. It’s also recommended that for weight loss and weight gain, adults increase their physical activity to at least 300 minutes per week. But based on their findings, the researchers are challenging “the basis for the current recommendations regarding exercise for weight management.”

The full study was published in the American Journal of Physiology