Exercise is tremendously beneficial to our health in many ways, but it’s not that effective when it comes to losing weight. A new analysis explains why.
It’s true that people who start exercising more burn extra calories. However, they don’t lose (nearly) as much weight as one would expect based on the additional calories burned.
An analysis of 14 trials in people last week in Current Biologyrevealed that our bodies compensate for the possible benefits of physical activity burning less energy on other things.
Furthermore, the compensation effect is greater if people eat less at the same time as they do more exercise, which can completely cancel out the extra energy spent exercising.
That is, although eating less results in weight loss, exercising while dieting may not result in any additional weight loss.
“The real problem here is that if you combine exercise with diet, your body says: ‘OK, then I’ll make up for more’”, explains, to , the leader of the investigation Herman Pontzerfrom Duke University in North Carolina.
“Exercising is still good for you, but not for losing weight”he added.
The new analysis focused on 14 trials involving, in total, around 450 people. On average, Pontzer and Trexler found that people’s total energy expenditure increased by only a third of what would be expected based on increased exercise.
For example, suppose people exercised enough to burn an additional 200 kilocalories per day. Your total energy expenditure, in these studies, only increased by about 60 kilocalories.
Continue to eat well
It was also found that, for people who continued to eat as usual, total energy expenditure increased, on average, by half of what would be expected. But for those who ate less while exercising more, total energy expenditure often did not increase.
The type of exercise also proved to be decisive: compensation occurred only with aerobic exercises, such as running.
With weight lifting or resistance training, energy use increased more than expected. For example, the total energy expenditure of people who spent an additional 200 kilocalories lifting weights increased by 250 kilocalories per day. Pontzer speculates that bodybuilders may be burning extra energy to repair and build muscle.
However, the people who did weight training in these studies gained muscle and lost almost no fat. “Therefore, it is still not a good way to lose weight”, notes the researcher.
There is one thing that is important to highlight: physical exercise is excellent for health.
