For the new study, published in the journal Marketing Letters, French and American researchers turned to psychology and the possible effect that calling exercise by any other name might have on peoples subsequent diets.
In that pursuit, the researchers first recruited 56 healthy, adult women, the majority of them overweight. The women were given maps detailing the same one-mile outdoor course and told that they would spend the next half-hour walking there.
Half of the women were told that their walk was meant to be exercise and the others were told that their 30-minute outing would be a walk purely for pleasure.
After the walk, those women whod been formally exercising reported feeling more fatigued and grumpy than the other women, although the two groups estimates of mileage and calories burned were almost identical. More telling, when the women sat down to a pasta lunch, with water or sugary soda to drink, and applesauce or chocolate pudding for dessert, the women in the exercise group loaded up on the soda and pudding, consuming significantly more calories from these sweets than the women whod thought that they were walking for pleasure.
For a follow-up experiment, the researchers directed a new set of volunteers, some of them men, to walk the same one-mile loop. Afterward, allowed to fill a plastic bag at will with M&Ms as a thank-you, the volunteers from the exercise group poured in twice as much candy as the other walkers.
To examine whether real-world exercisers behave similarly to those in the experiments, the researchers visited the finish line of a marathon relay race. They asked the runners whether they had enjoyed their race experience and offered them the choice of a gooey chocolate bar or healthier cereal bar. In general, those who said their race had been difficult or unsatisfying picked the chocolate; those who said that they had fun gravitated toward the healthier choice.
- GRETCHEN REYNOLDS