New research conducted at Cornell University indicates that runners eat less after a run if they find it enjoyable rather than hard work.
In the last decade, Brian Wansink has gained considerable recognition for investigating how perception influences appetite and calorie consumption. He is perhaps best known for his book Mindless Eating: Why we eat more than we think.
In the new studies, the researchers begin by acknowledging that many runners and other exercisers are disappointed when they don't lose as much weight as they hoped. Why not? Often, it’s because they consume too many calories after working out. That is, they think exercise gives them license to eat more.
To examine this hypothesis, Wansink and colleagues asked two groups of subjects to take a 30-minute walk around a college campus. One group was told they were exercising. A second group walked an identical campus course, but was told to have fun by listening to provided music players while they walked. Afterwards, the groups were given a buffet lunch and told to choose their beverage and dessert, either soft drink and chocolate pudding, or water and applesauce.
Both groups ate the same amount from the buffet lunch. But the exercise walkers consumed an average of 134 calories (of drink and pudding), while the fun walkers consumed 94. In other words, the perception of a 30-minute "exercise" walk increased their license to eat more “hedonic” foods by roughly 50 per cent.
The researchers also studied 231 runners in a marathon-relay race. Each runner ran a 5K, 10K, or 7.195K relay leg. After finishing, the runners were given a short questionnaire asking if they had enjoyed the run, or if they had found it a hard, competitive effort. Finally, they were allowed to choose a chocolate bar (relatively unhealthy) or a cereal bar (relatively healthy). The bars were wrapped in plain vanilla envelopes to eliminate any brand preferences.
Statistical analysis revealed a significant difference in bar selection: “The participants who had more fun during the race were more inclined to choose the cereal bar than participants who had less fun.”
The authors make two general conclusions regarding their work on exercise and hedonic food consumption (i.e., basically junk food). First, public health officials and the exercise industry should do more educational work to inform exercisers about the potential negative effects of overeating after exercise.
Second, consumers should “reframe” their exercise activity as fun rather than hard work. The researchers suggest things such as listening to music, making a phone call to friends, or watching a video while running or walking on a treadmill.
These findings are consistent with research on how perception of the type of workout can affect food choices.