Cell recycling makes exercise good for you

of Texas in Dallas discovered that, in mice, autophagy - the process by which a cell recycles dispensable components for extra energy - increases 30 minutes into exercise.

Exercise protects against diabetes by increasing glucose uptake. Levine's team wondered whether autophagy might be involved, so compared the effects of exercise on normal mice and mutant mice that could not increase autophagy. The normal mice shed excess fat and reversed early signs of diabetes, while the mutants only lost fat .

Rather than just providing fuel, exercise-induced autophagy appears to help cells fine-tune their glucose metabolism. Drugs that boost autophagy may mimic these effects, says Levine.