The truth about exercise and weight loss | MNN

When you want to lose weight, you do two things: eat less and do more exercise.

Just cutting calories should make you lose weight. But exercise alone is rarely enough to lose weight. Life is not fair, after all.

Think of it this way: when it comes to a brisk walk of 30 minutes at about 4 miles per hour (ie a 15-minute mile), a 155-pound person burns about 167 calories, according to the Harvard Medical School. Do you want to celebrate your achievement? This exercise is quickly erased by a large scoop of vanilla ice cream or two small chocolate chip cookies.

If you like more serious exercises, 30 minutes of vigorous stationary cycling burn 391 calories. But this is erased with a slice of pepperoni pizza.

It does not seem fair that all these efforts can be canceled by a few bites of tasty dishes.

Is more exercise the answer?

We tend to overestimate the number of calories we burn when we exercise and often eat a lot to compensate. (Photo: Arturs Budkevics / Shutterstock)

This sounds like a simple math: if you exercise for x minutes, you will burn more calories, so do more exercise and burn more calories. But research shows that it is not so easy.

Recently, New Scientist explained this by telling a story entitled "Why do more exercise will not help you burn more calories". Scientific writer Teal Burrell explored the idea of ​​the so-called paradox of exercise. People who significantly increase their training regimen often find that despite all the sweat and movement, they lose a few pounds. Scientists have several theories to explain this.

They eat more. You've done an exhausting trek and you're so proud of yourself. You then reward yourself with a chocolate shake. People tend to overestimate the calories they burn when they are exercising. In one study, people worked on a treadmill and were told to eat at the buffet the amount of food equivalent to the calories they thought they would burn. They badumed that they had burned about 800 calories and had eaten about 550, while they had actually burned only 200.

They move less. You did this exhausting hike in the morning, so you spread yourself on the couch the rest of the day. Another theory is that people make up for their workouts by remaining sedentary the rest of the time. These are called "compensatory behaviors" when displacement and non-displacement balance. But exercise physiologist Lara Dugas of Loyola University does not accept this idea. "It does not mean you lose that 500 calorie run because you're sedentary for the rest of the day," she told New Scientist. "It does not make sense."

The body adapts. The most logical theory seems to be that when you exercise more, your body adjusts by spending less energy on internal functions, from the immune system to digestion. Researchers believe that systems that work in the background, spending calories, simply become more effective when you exercise more.

The role of exercise

Some nutritionists think that weight loss equals about 80% diet and 20% exercise. (Photo: Billion photos / Shutterstock)

Kevin Hall, a mathematician and obesity researcher, explained to Vox why adding extra physical activity would not likely result in significant weight loss. Hall used the National Institutes of Health's bodyweight planner to calculate that, if a 200-pound man added 60 minutes of average-intensity physical activity four days a week for a month, while maintaining his identical caloric intake, he would lose five pounds. "If that person decided to increase their food intake or to relax more to get extra exercise, they would lose even less weight," said Hall.

So, if someone is trying to lose a lot of weight, it would take a lot of time and effort to try and lose weight based solely on exercise.

But of course, this does not mean that you should cancel your membership in a sports club and throw your sneakers in the back of your wardrobe. Exercise is always a key part of weight loss to one or two shots. You just have to combine it with calorie control.

Nutritionists will say that weight loss is about 80% diet and 20% exercise. So yes, watch for brownies and snacks if you are trying to lose the love handles, but keep moving forward. It's a combination of eating-moving that requires smart feeding and regular movements to be healthy. Sometimes being fit does not seem right. But it's worth it.

The truth about exercise and weight loss

Eating less is more important than exercise if you want to lose weight.