Emotional responsiveness during and after cycling exercise

Abstract

The first experiment examined emotional responsiveness during an experimental manipulation of arousal. 24 healthy females completed counterbalanced conditions of 20 minutes of very low and low intensity cycling exercise and seated rest. Startle and corrugator supercilii responses, and baseline orbicularis oculi and corrugator supercilii EMG activity, were measured during each condition while participants viewed pleasant, neutral and unpleasant slides. Very low and low intensity exercise did not alter theamplitude of the startle response or corrugator supercilii responses compared to the control condition. Baseline orbicularis oculi EMG did not change during exercise. Baseline corrugator supercilii EMG significantly increased during low intensity exercise compared to during seated rest. The results of experiment 1 suggest that mildly painful, low intensity exercise-induced arousal is insufficient to alter emotional responsiveness as assessed by the acoustic startle eyeblink response and corrugator supercilii EMG responses during the viewing of pleasant, neutral, and unpleasant slides. This suggests that the construct of arousal, in the context of a valence-arousal theory of emotion, should be conceptualized as brain activation related to the intensity of pleasant or unpleasant feelings rather than as peripheral autonomic, cardiovascular, or metabolic arousal. In experiment 2, the influence of low and moderate intensity exercise on post-exercise changes in anxiety, startle response amplitude and corrugator supercilii muscle activity was determined. 24 healthy females completed counterbalanced conditions of 25 minutes of low and moderate intensity cycling exercise and seated rest. Startle and corrugator supercilii responses, as well as baseline corrugator supercilii EMG activity, weremeasured immediately prior to and 20 minutes after each condition while participants viewed pleasant, neutral and unpleasant slides. State anxiety was significantly reduced 20 minutes after each condition, as was startle amplitude to each type of slide. Baseline corrugator supercilii EMG activity did not change after seated rest, but decreased in an exercise intensity-dependent fashion after cycling. Corrugator supercilii EMG responses during the slides were not different between or after the conditions. The findings suggest that anxiolytic conditions of low and moderate intensity cycling and seated rest are relatedto decreased startle amplitude but do not reflect changes in appetitive or defensive responsiveness.