Exercise won't help you lose weight. Here's the disappointing reason why

“Exercise burns calories and helps you lose weight,” is a very popular saying. 

A new study that looked at how exercise affects our metabolism found that for every 100 calories we expect to burn as a result of exercise, most of us actually burn less than 72 calories. This means that simply closing your mouth is a more effective exercise than running.

Research shows that our body tends to automatically compensate for at least a quarter of the calories we expend during exercise, and undermines our efforts to lose weight through working out. The results also show that people with extra pounds suffer from caloric compensation, which makes weight loss through exercise even more elusive for them. 

Yet research also suggests that calorie compensation varies from person to person, and that learning how a person’s metabolism responds when he/she works out may be the key to optimizing exercise for weight control.

As we all know, in theory, exercise significantly helps with weight loss. As we move, our muscles contract and more energy is needed to activate one’s body. The amount of energy required varies from person to person, but by and large in order to lose weight we need to burn more calories than we consume that day.

But this result rarely occurs. Quite a few past studies have found that most people who start a new workout program lose weight more slowly than expected based on the number of calories they burn during their workout, even if they strictly maintain their diet.

Quite a few studies conducted in recent years have shown that more exercise doesn’t necessarily result in a higher daily expenditure of calories. But few large-scale experiments have attempted to find out how much our body compensates for the calories burned while on the move, as measuring metabolic activity in humans is complex and expensive.

Annoying data

In a new study published in August in the journal Current Biology, several scientists decided to examine what happens to our metabolism when we work out. They used data from 1,754 adults that included their body metrics and expenditure of their basal energy, meaning how many calories they burn simply by living, even if they’re always on the couch. 

Then, using statistical models, the researchers were able to tell if the calories burned during an activity increased people's daily energy expenditure as expected, meaning if people burn relatively more calories as they move more. But researchers found they didn’t tend to burn more calories.

In fact, most people seem to burn on average only about 72% of the calories they would be expected to burn during their normal daily routine. Another statistic showed that energy compensation levels have risen among people with relatively high levels of body fat and they’re prone to compensate for 50% or more of calories burned by exercise.It’s important to note that the study didn’t examine people's daily food intake. It focused solely on energy expenditure and how our body appears to be able to offset some of the calories burned during exercise by reducing biological activity elsewhere in the body.

The researchers concluded that ‘exercise burns a few calories, period.” They also said that “to lose weight, you need to eat less.”

But just before concluding, it’s important to remember that despite the data found in the present study, even people whose bodies compensate for 50% or more of the calories they expend during exercise will burn more calories a day than people who never leave the house.