Can the placebo effect work with exercise and fitness? Two Harvard psychologists decided to find out, and the results were startling.
84 maids at seven carefully matched hotels [were quizzed on] how much exercise they got. Fully a third of the women said they got no exercise at all, while two-thirds said they did not work out regularly. Langer and Crum took several measures of the women’s basic fitness levels, which indicated that they, indeed, had the poor health of basically sedentary people. Then just over half the women were told an unfamiliar truth: cleaning 15 rooms daily — pushing recalcitrant vacuum cleaners, scrubbing tubs, pulling sheets — constitutes more than enough activity to meet the surgeon general’s recommendation of a half-hour of physical activity daily. [The] control group was left in the dark.
A month later, Langer and Crum checked back with the women to find, as they reported in the February issue of Psychological Science, remarkable results. The average study-group maid had lost 2 pounds, while her systolic blood pressure had dropped by 10 points; by all measures the 44 women “were significantly healthier.” Yet there were no reported changes in behavior, only in mind-set.