While it’s tempting to hit the gym when it’s cold, slushy or icy outside, it might be worthwhile to rethink that habit. In a recent New York Times article, Gretchen Reynolds reports that research now suggests that outdoor exercise offers more than machines in a gym do. “You stride differently when running outdoors, for one thing. Generally, studies find, people flex their ankles more when they run outside. They also, at least occasionally, run downhill, a movement that isn’t easily done on a treadmill and that stresses muscles differently than running on flat or uphill terrain. Outdoor exercise tends, too, to be more strenuous than the indoor version. In studies comparing the exertion of running on a treadmill and the exertion of running outside, treadmill runners expended less energy to cover the same distance as those striding across the ground outside, primarily because indoor exercisers face no wind resistance or changes in terrain, no matter how subtle.” More energy is expended due to wind drag in cycling outside as well.
Recent studies have shown staggering psychological benefits to exercising outdoors. Older adults were more committed to their workouts, more physically active in general and felt happier. “A few small studies have found that people have lower blood levels of cortisol, a hormone related to stress, after exerting themselves outside as compared with inside. There’s speculation, too, that exposure to direct sunlight, known to affect mood, plays a role.”
No matter what the reason, more outdoor exercise is a good thing. According to Jacqueline Kerr, a professor at the University of California, San Diego, who led the study of older adults, “despite the fitness industry boom, we are not seeing changes in national physical activity levels, so gyms are not the answer.”