Science Translational Medicine: Chemicals Related to Metabolism Play Important Role in Exercise

Chemically speaking, you become a different person when you run, according to new research in Science Translational Medicine that maps how chemicals change in the blood during exercise.

The study, by Gregory Lewis and colleagues from Massachusetts General Hospital, identified chemical switches in the body that are distinctly different during exercise in more-fit people versus less-people.

Breaking a sweat and getting the heart pumping fast through movement is known to protect against many diseases and prolong lifespan, but why exercise results in these overwhelmingly positive effects remains obscure.[PHOTOGRAPH] A crowd of marathoners running across a bridge [Photo © and licensed by Getty Images, #87560677]

The findings shed new light on how exercise influences metabolism, and may lead to the development of new diagnostic tests to assess fitness, along with state-of-the-art supplements to replenish lost metabolites after exercise. (Think of gulping down an energy drink chock-full of metabolites after a run.)

Every energy-using activity in the body results in the production of metabolites, leftover substances measured in the blood that result from the metabolism or break-down of the original substance. A blood sample contains hundreds of these metabolites that could one day provide a chemical ‘snapshot’ of an individual’s health status.

Now, Lewis and colleagues show that fit individuals have a distinctly different set of changes in metabolites than less fit individuals. The researchers used high-sensitivity mass spectrometry to measure 200 blood metabolites in a group of participants before, during, and after exercise on a treadmill.

The data revealed that fit individuals had a 98% increase in the breakdown of stored fat, sugar, and amino acids, while less-fit people had only a 60-70% increase. An additional highly-fit group who ran the Boston marathon had a striking 1128% increase.

The results show that more-fit individuals—whether inherently or through training—have different biochemical changes in the bloodstream that enable them to burn calories more efficiently than less-fit individuals.

Science Translational Medicine, the newest journal from Science, focuses on outstanding science with promise to improve human health and quality-of-life. Under the direction of Elias Zerhouni, chief scientific adviser and former director of the National Institutes of Health, and Editor Katrina Kelner, the journal aims to publish groundbreaking research from basic biology that will help make significant advances in medical care, along with commentary on the latest issues in translational medicine.