Exercising for long periods of time doesn't burn more calories, study finds

Experts have stressed that while exercise is important, diet is also key to weight loss

(Sean Gallup/Getty Images)

Gym-goers who spend long periods of time exercising in the hope that they will burn more calories could be wasting their time, a new study has shown.

US researchers found that the metabolism adapts to the amount of exercise a person does, meaning those attempting to lose weight should not rely on exercise alone.

The study published in the journal ‘Current Biology’ showed that those who undertake moderate levels of activity used up the most calories.

Meanwhile, the level of calories burned by subjects who exercised more than average plateaued.

Researchers at the City University of New York measured the amount of energy more than 300 men and women used on a daily basis over the course of a week.

The evidence showed that participants who lead moderate lifestyles – by cycling to work or visiting the gym twice a week – burned 200 calories more than those who were sedentary.

However, those who rose above what scientists described as a “sweet spot” did not burn any extra calories.

The findings highlight the importance of diet when attempting to lose weight, the study said.

Lead scientist Dr Herman Pontzer stressed that the study does not mean that exercise is not beneficial, however.

“Exercise is really important for your health. That's the first thing I mention to anyone asking about the implications of this work for exercise.

”There is tons of evidence that exercise is important for keeping our bodies and minds healthy, and this work does nothing to change that message.

“What our work adds is that we also need to focus on diet, particularly when it comes to managing our weight and preventing or reversing unhealthy weight gain.”

Dr Pontzer said he chose to better understand the link between exercise and energy spent after he worked with the Hadza people of northern Tanzania, Africa.

The community are “incredibly active” hunter-gathers who walk long distances each day – however they had similar daily energy expenditures to people living more sedentary, modernised lifestyles in the United States and Europe.

“That was a real surprise,” said Dr Pontzer.

“The most physically active people expended the same amount of calories each day as people who were only moderately active,” he added.

Additional reporting by PA