Jan. 29, 2010 -- What you eat after working out makes a difference, but it doesn't mean you have to starve yourself to reap the health benefits of exercise.
A new study shows that eating a low-carbohydrate meal after aerobic exercise enhances insulin sensitivity. Increased insulin sensitivity makes it easier for the body to take up sugar from the bloodstream and store it in muscles and other tissues where it can be used for fuel.
Impaired insulin sensitivity, or insulin resistance, increases the risk for type 2 diabetes and heart disease.
Researchers say the results support a growing body of research that shows many of the health benefits of exercise come from the most recent exercise session rather than weeks or months of training.
“Many of the improvements in metabolic health associated with exercise stem largely from the most recent session of exercise, rather than from an increase in ‘fitness’ per se,” researcher Jeffrey F. Horowitz of the University of Michigan says in a news release. “But exercise doesn’t occur in a vacuum, and it is very important to look at both the effects of exercise and what you’re eating after exercise.”
Eating Affects Health Benefits of Exercise
The study, published in the Journal of Applied Physiology, looked at the effects of three different meals on the body's metabolism after 90 minutes of moderate exercise on a treadmill and stationary bicycle compared with resting metabolism in nine healthy men.
- The first meal consisted of a balanced meal with a carbohydrate, fat, protein, and calorie content that matched their calorie expenditure during the exercise session.
- The second meal matched the calorie count of their exercise expenditure but contained about 200 grams of carbohydrates (less than half the carbohydrate of the balanced meal).
- The third meal contained fewer calories than those burned during the aerobic workout (about one-third less than the other two meals) and a relatively high carbohydrate content.
In all three exercise sessions, researchers say there was a trend for an increase in insulin sensitivity. But when the participants ate the low-carbohydrate meal following exercise, it increased their insulin sensitivity even more.
Researchers say the results show that people can reap important health benefits from exercise without starving themselves after exercise or losing weight.