It is unclear how exercise influences affect in overweight and obese individuals.
Objectives: To examine the effect of a single exercise session on positive and negative affect and examine whether pre- to post-exercise changes in affect influence subsequent energy intake (EI).
Methods: Nineteen sedentary, overweight/obese women walked for ~40 minutes at a moderate-intensity on one day and rested for a similar duration on a separate day. Positive (PA) and negative affect (NA) were assessed pre-testing, post-testing, 60, and 120 minutes post-testing using the Positive and Negative Affect Schedule. Energy intake was determined by measuring food intake before and after a buffet meal 1-2 hours post-exercise/rest.
Results: For PA, the time x condition interaction was significant (p<0.05). There was a trend for those subjects with improved PA from pre to post-exercise (58%) to consume fewer calories post-exercise (524 ± 260.9 kcal) compared to post-rest (566.1 ± 303.0 kcal), while those who had a worsening or no change in PA (42%) had a higher EI following exercise (588.0 ± 233.7 kcal) compared to rest (524.6 ± 281.7 kcal; p=0.08). NA was not significantly altered by exercise.
Conclusions: Some overweight/obese individuals appear to experience an increase in positive affect with exercise; however, there is a high degree of individual variability in responses that warrants further examination. This study also provides initial evidence that a worsening in affect following exercise may unfavorably impact eating behaviors. These preliminary findings have the potential to enhance our understanding of factors mediating the relationship between exercise and EI.
Keywords: Affect; Mood; eating behaviors; food intake; negative affect; obesity; physical activity; positive affect.