Effect of Fed State on Self-selected Intensity and Affective Responses to Exercise Following Public Health Recommendations

Nutritional status has numerous effects on exercise metabolism and psychological responses. The effect of fed state on changes in affective valence; however, are unknown. Thus, the present study examined how fed state influenced self-selected exercise intensity, affective responses during exercise, and exercise enjoyment when exercise was completed following physical activity guidelines for public health. In a repeated-measures crossover design, 25 recreationally active men and women (age and BMI = 22.0 ± 2.0 yr and 24.3 ± 3.3 kg/m) performed a single 30 min session of treadmill exercise at a Rating of Perceived Exertion (RPE) equal to 13 on the Borg 6-20 scale following an overnight fast (FAST) or 30 minutes after a small meal (FED). Affective valence was recorded every 3 minutes during exercise. Heart rate and gas exchange data were measured continuously using a metabolic cart, blood glucose and blood lactate concentration were measured pre/post-exercise, and enjoyment was measured 15 minutes post-exercise. There was no effect of condition on affective valence, enjoyment, or self-selected intensity (all ). However, pre-exercise blood glucose was higher in FED pre-exercise, but higher post-exercise in FAST (<0.05). Blood lactate concentration was also higher in FAST (<0.05). Our results reveal minimal effects of a small, high-carbohydrate pre-exercise meal on in-task and post-task affective responses, exercise enjoyment, and self-selected intensity. These data suggest that an overnight fast does not alter affective valence or reduce enjoyment of continuous exercise.