Physical activity does not disturb the measurement of startle and corrugator responses during affective picture viewing

Healthy college females (n=24) completed counterbalanced conditions of 20 min of very low and low intensity cycling exercise and seated rest. Startle and corrugator supercilii responses, and baseline orbicularis oculi and corrugator supercilii electromyographic (EMG) activity, were measured during each exercise condition while participants viewed pleasant, neutral and unpleasant pictures. The exercise conditions did not alter the magnitude of the startle or corrugator responses compared with the resting control condition. Baseline orbicularis EMG increased slightly and baseline corrugator EMG increased significantly, during the low intensity exercise condition. In conclusion, low intensity physical activity is not sufficient 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 pictures. Despite modestly increased baseline EMG levels, reliable startle and corrugator EMG responses can be obtained in healthy college females during picture viewing while performing low intensity cycling exercise.