A small molecule produced by muscles in response to exercise boosts metabolism in other tissues.

Robert Gerszten of Massachusetts General Hospital in Boston and his colleagues discovered the molecule, BAIBA, when they forced muscle cells to express the metabolic regulator PGC-1α — levels of which increase with exercise. BAIBA levels increased in exercising mice. In animals treated with BAIBA, white fat tissue showed greater expression of genes linked to calorie burning, and the mice gained less weight and had better glucose metabolism than untreated mice.

The researchers also found an inverse association in humans between BAIBA levels and heart-disease risk factors — people with more BAIBA in their blood also had decreased cholesterol levels and less insulin resistance, for instance. BAIBA could be a target for drugs that treat diabetes and other metabolic disorders, the authors say.

Cell Metab. 19, 96–108 (2014)