“What's the point?” many people think, when their modest exercise routines don't bring the weight loss they hope. Increasing the amount of exercise you get does have value, even without weight loss, a new study shows. It offers an enormous health benefit — it reduces your risk of prediabetes and diabetes.

People who are fit — even those who are overweight — are less likely to go on to develop diabetes.

Being aerobically fit, known as cardiorespiratory fitness (CRF) fitness, may or may not help you lose weight, (what you eat has a lot to do with that), but “CRF does reduce the risk of developing diabetes and prediabetes,” Lisa Chow, an author of a new study, told TheDoctor. People who are fit — even those who are overweight — are less likely to go on to develop diabetes.

“A lot of studies have looked at baseline fitness and the development of prediabetes and diabetes over time,” Chow said. But these studies were limited by a largely male study population, a shorter study duration (five to seven years) and measuring CRF at different intervals prospectively.

The team charted the cardiorespiratory fitness of nearly 4400 men and women three times over 20 years. Even when changes in weight, as measured by body mass index (BMI), were taken into account, the researchers found better CRF was still associated with a lower risk for developing prediabetes and diabetes. “That is the one thing that surprised us,” said Chow, an associate professor of medicine at the University of Minnesota.

The women and men were part of the Coronary Artery Risk Development in Young Adults (CARDIA) study. Resarchers assessed CRF by treadmill exercise testing at the beginning of the study, year 7 and in year 20. The scientists also tested study participants for the development of diabetes and prediabetes at baseline, year 7, year 10, year 15, year 20 and year 25.

Increasing the amount of exercise you get does have value, said Chow. She added, “Some people feel if they exercise more without losing weight, it is stupid. But there is still a benefit, however small.” It is important to try and get exercise, even if there is no change in weight. And if you increase exercise and lose weight you will see even greater benefits.

The study is published in Diabetologica.