Turns out, quite a bit. A new study from the University of Bath in England, published in The Journal of Physiology, looked at the importance of exercising on a daily basis amid periods of high caloric consumption (i.e. the entire holiday season). A group of otherwise healthy young men was divided into two groups — half were instructed to run on a treadmill at moderate intensity for 45 minutes every day, while the other half were told to restrict their physical activity to under 4,000 steps per day. Each group was given a diet plan that increased net caloric intake by 50%. For the exercise group, this meant a diet that included 75% more calories than they normally ate, in order to offset the calories burned on the treadmill.
After one week, researchers noted that the couch-potato group was already experiencing significantly lower blood-sugar control, as well as a change in fat-cell gene expression that suggested a long-term decline in metabolic function. The exercise group, on the other hand, displayed normal blood-sugar control, as well as healthier fat-cell gene expression. Essentially, even though their calorie intake was way higher than normal, the subjects who had exercised regularly were able to offset the potentially harmful long-term effects of over-consumption.
While the idea of emerging from our cozy blanket fort on Black Friday to go for a run still makes us sort of ill, this research could be a big deal in terms of understanding the best way to incorporate exercise into our lives. Whenever we hear "experts" talking about the importance of regular exercise, it's often difficult to parse out exactly how much is needed — and how that time should be spread out throughout the week. This study suggests that the key to an optimal metabolism may be more complicated than simply "calories in, calories out." Of course, this study included only male subjects; we look forward to seeing similar research on the relationship between overeating and exercise and its effect on women's metabolism. Still, the results are compelling — and may even make us think twice about our slothful holiday tendencies. (The New York Times)