Can You Lose Weight Just By Exercising?

Weight loss is a tricky conversation to have. A client asked me last week, "How much exercise do I need to do to lose this weight?!"

I've known a lot of people who wanted to lose weight and would happily walk every waking hour if they just didn't have to change their eating habits.

It's not that simple and it's not a mathematical equation so forget all you've read about how "you can burn off X calories by doing this...."

When researcher Herman Pontzer studied the Hadza, a hunter-gatherer tribe in Tanzania, he expected to find they burned an enormous number of calories. They’re always on the move—walking, running, lifting, and working hard.

But when he and his team compared their daily energy use to that of an average office worker in the U.S., they were shocked: the numbers were nearly the same.

This discovery led him to develop a theory about how our bodies use energy, called the “constrained total energy expenditure model.”

It suggests that our bodies adjust how they burn calories. If we’re more active, the brain slows down other processes to compensate, keeping our total calorie burn at the same level.

Burning more calories through exercise doesn’t necessarily mean losing more weight.

When Pontzer compared active people with those who are sedentary, he discovered that they burned the same number of calories.

People rarely lose much weight with exercise, even though the exercise makes them healthier.

What we know about metabolism

🔥 Men and women burn calories at about the same rate. Muscle mass, not gender, is the deciding factor.

🔥 Our metabolism doesn't slow down in middle age. It stays steady until around age 60, when it starts to slow down.

🔥 Middle-age weight gain isn’t about metabolism. It’s more about changes in eating and activity levels.

🔥 We burn the most calories in our late teens.

🔥 Exercising more doesn’t always mean burning more calories. The body adjusts by spending less energy elsewhere.

🔥 Nothing you eat can boost your metabolism. Digestion burns about 10% of the calories you consume.

You can't outrun your fork

Movement does so much more for our health than controlling weight.

Regular exercise reduces inflammation, lowers stress, strengthens muscles, and keeps our hearts and minds sharp. These changes contribute to better overall health, increased longevity, and a lower risk of chronic diseases.

The takeaway? While you can’t out-exercise a poor diet, movement is essential for overall well-being. Rather than focusing on burning calories, think of exercise as the ticket to inestimable health benefits—stronger muscles, better heart health, improved mental well-being, and greater quality of life!