The physical rewards of exercise derive not just from muscular exertion but, to a surprising extent, from a person's mind-set about exercise, a new report suggests.
Alia J. Crum and Ellen J. Langer, psychologists at Harvard University, made this provocative discovery when they studied 84 women who clean rooms at seven Boston-area hotels. It's a physically taxing job. Each woman scours a hotel room for 20 to 30 minutes, cleaning an average of 15 rooms daily.
For at least a month, women who had heard a brief presentation that explained how their work qualifies as good exercise displayed more weight loss, larger blood pressure declines, and other health advantages compared with peers given no such information, Crum and Langer say.
This finding suggests that exercise enhances physical health, at least in part, via the placebo effect—that is, as a consequence of an individual's beliefs and expectations. "If our mind-sets control our psychological and physical rea