What You Eat After Exercise Matters

The nature of the health benefits of aerobic exercise can be greatly affected by the food we eat afterwards, according to a study published in the Journal of Applied Physiology. Specifically, the study found that exercise enhanced insulin sensitivity, particularly when meals eaten after the exercise session contained relatively low carbohydrate content.

Enhanced insulin sensitivity means that it is easier for the body to take up sugar from the blood stream into tissues like muscles, where it can be stored or used as fuel. Impaired insulin sensitivity (i.e., "insulin resistance") is a hallmark of Type II diabetes, as well as being a major risk factor for other chronic diseases, such as heart disease.

Interestingly, when the research subjects in this study ate relatively low-calorie meals after exercise, this did not improve insulin sensitivity any more than when they ate enough calories to match what they expended during exercise. The study suggests that you don't have to starve yourself after exercise to still reap some of the important health benefits.

Subjects were tested during four hospital visits that differed primarily by the meals eaten after exercise. The following describes the four different visits:

1. They did not exercise and ate meals to match their daily calorie expenditure. This was the control trial.
2. They exercised for approximately 90 min at moderate intensity, and then ate meals that matched their caloric expenditure. The carbohydrate, fat, and protein content of these meals were also appropriately balanced to match their expenditure.
3. They exercised for approximately 90 min at moderate intensity and then ate meals with relatively low carbohydrate content, but they ate enough total calories to match their calorie expenditure. This reduced-carbohydrate meal contained about 200 grams of carbohydrate, less than half the carbohydrate content of the balanced meal.
4. They exercised for approximately 90 min at moderate intensity and then ate relatively low-calorie meals, that is, meals that provided less energy than was expended (about one-third fewer calories than the meals in the other two exercise trials). These meals contained a relatively high carbohydrate content to replace the carbohydrate "burned" during exercise.
   

The exercise was performed on a stationary bicycle and a treadmill. The order in which the participants did the trials was randomized. In the three exercise trials, there was a trend for an increase in insulin sensitivity. However, when participants ate less carbohydrate after exercise, this enhanced insulin sensitivity significantly more. Although weight loss is important for improving metabolic health in overweight and obese people, these results suggests that people can still reap some important health benefits from exercise without undereating or losing weight.

Bonnie - music to my ears. 15-20 minutes after exercise, nothing is better than some lean protein and little carb.