Hotel cleaners who were told that their work of cleaning roughly 15 rooms each day was enough physical activity to maintain a healthy lifestyle were more trim and fit four weeks later than their peers who weren't given this message. Ellen Langer and her student Alia Crum report in this month's issue of Psychological Science.
While the placebo effect of fake pills is widely accepted, the researchers noted that no one has yet studied whether the belief that exercise is maintaining fitness might exert a kind of placebo effect.
To investigate the researchers recruited 84 female housekeepers working at seven different hotels. Workers at four of the hotels were told that the exercise they got on the job met or exceeded the U.S. Surgeon-Generals activity recommendations for a healthy lifestyle, while those in the 3 other hotels weere not told anything.
One possible explanation for the results could be that women in the informed group became more active and ate more healthily, but the scientists found that this was not the case, making it unlikely that the fitness improvements were due to changes in behaviour.
"Whether the change in physiological health was brought about directly or indirectly, it is clear that health is significantly affected by mind-set," the scientists say.
Reuters News Agency,