What You Eat after Exercise Shapes You

Senior study author, Jeffrey F. Horowitz of the University of Michigan, states that, "Differences in what you eat after exercise produce different effects on the body's metabolism." 

The study follows up on several previous studies that demonstrate that many benefits of exercise are transient: one exercise session produces benefits to the body that taper off, generally within hours or a few days.

"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," Horowitz said.

"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," he said.

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 2 diabetes, as well as being a major risk factor for other chronic diseases, such as heart disease.

But the study also found that one does not have to starve after exercise to reap its benefits.

The study is based on healthy sedentary men, aged between 28 and 30 years.

Journal of Applied Physiology, Feb. 2010