This week marks the start of the annual eat-too-much and move-too-little holiday season, with its attendant declining health and surging regrets. But a well-timed new study suggests that a daily bout of exercise should erase or lessen many of the injurious effects, even if you otherwise lounge all day on the couch and load up on pie.
To undertake this valuable experiment, which was published online in The Journal of Physiology, scientists at the University of Bath in England rounded up a group of 26 healthy young men. All exercised regularly. None were obese. Baseline health assessments, including biopsies of fat tissue, confirmed that each had normal metabolisms and blood sugar control, with no symptoms of incipient diabetes.
The scientists then asked their volunteers to impair their laudable health by doing a lot of sitting and gorging themselves.
Energy surplus is the technical name for those occasions when people consume more energy, in the form of calories, than they burn. If unchecked, energy surplus contributes, as we all know, to a variety of poor health outcomes, including insulin resistance — often the first step toward diabetes — and other metabolic problems.
Overeating and inactivity can each, on its own, produce an energy surplus. Together, their ill effects are exacerbated, often in a very short period of time. Earlier studies have found that even a few days of inactivity and overeating spark detrimental changes in previously healthy bodies.
Some of these experiments have also concluded that exercise blunts the ill effects of these behaviors, in large part, it has been assumed, by reducing the energy surplus. It burns some of the excess calories. But a few scientists have suspected that exercise might do more; it might have physiological effects that extend beyond just incinerating surplus energy.
To test that possibility, of course, it would be necessary to maintain an energy surplus, even with exercise. So that is what the University of Bath researchers decided to do.
Their method was simple. They randomly divided their volunteers into two groups, one of which was assigned to run every day at a moderately intense pace on a treadmill for 45 minutes. The other group did not exercise.