The latest issue of Harvard Magazine features researchers in the new field with the offputting name of metabolomics — the study of metabolites or chemicals in the blood. The piece focuses on Harvard researchers Robert Gerszten and Greg Lewis, and mentions an experiment that highlighted the dramatic effects of exercise at our most basic levels:
Last year, Gerszten and Lewis ran an experiment to examine the effects of just 10 minutes of exercise on about 200 common metabolites. The pair had asked a group of patients that included healthy people—the “worried well”—to run for approximately 10 minutes on a treadmill. Blood samples were taken before exercise, at peak exercise as the test ended, and again an hour later.
After adjusting for age, peak exercise capacity is the most powerful known predictor of the risk of death among healthy people and those with cardiovascular disease. Even among those with cardiovascular disease, Gerszten notes, those individuals who nevertheless can exercise intensely on a treadmill have the same risk of sudden death as “the guy who has never had a diagnosis of heart disease.” The challenge is to understand why exercise counteracts disease.
Despite the brevity of their treadmill challenge, Gerszten and Lewis discovered that profound changes took place in the biochemical profiles of their patients’ blood. Glycerol, a marker of the body’s ability to burn fat, was up. Glucose-6-phosphate, an indicator of the use of energy stored as glycogen in the liver and muscles, increased. So did pantothenate, a modulator of fatty acid oxidation, and allantoin, a marker of oxidative stress. The human body turns on the systems of energy utilization and the mechanisms for dealing with the potentially harmful by-products of oxidative processes (free radicals) very quickly.
My primitive takeaway: Does exercise kind of squeegee out your blood? We know a lot about how exercise improves health, and we’re coming to understand it better all the time. Maybe we’ll eventually understand it well enough to duplicate it in a pill, but that day will come long after our current pairs of sneakers are worn out…