When people exercise regularly over a long time, their bodies may lower energy use in other functions, such as metabolism or cellular processes, which can reduce the amount of weight lost compared to what would be expected based on calories burned through exercise alone.

Some people stop losing weight even when they keep exercising and eating the same amount, because their bodies may lower energy use in other functions to balance out the extra activity.

After losing weight through dieting, keeping the weight off typically requires higher levels of physical activity because the body naturally reduces energy use and increases hunger, making it difficult to maintain weight loss by eating less alone.

When people increase their physical activity beyond a certain point, their total daily energy burn stops increasing because the body reduces other movements and metabolic processes, making additional exercise less effective for losing weight.

The more you move each week while dieting, the more fat you tend to lose, even if you’re eating the same amount.

Regular physical activity that keeps energy use high may help maintain a higher resting metabolic rate and lower the risk of losing metabolic function and gaining weight as people age.