Abstract
Exercise at a self‐selected intensity has been shown to reliably improve affect, but its effect on state anxiety has not been rigorously investigated. Further, the postulated role of anxiety sensitivity within the anxiolytic effect of exercise is not yet fully understood. This study investigated the effect of an acute bout of self‐selected intensity exercise on anxiety, anxiety sensitivity, and affect. Inactive adults ( n = 39) with elevated trait anxiety (Spielberger Trait Anxiety Inventory score ≥ 40) were randomised to undertake either 20 min of self‐selected intensity aerobic exercise or static stretching (comparison group). State anxiety and anxiety sensitivity were measured before and after exercise. Affect was measured before, during, and after exercise. Results showed that the aerobic group selected a vigorous intensity (81–83%HR peak ), while the stretching group exercised at a significantly lower intensity (45–48%HR peak ). From pre‐ to post‐exercise, state anxiety significantly decreased ( p = 0.002, η2 = 0.12) and affect was significantly more positive ( p = 0.02, η2 = 0.07) across all participants. There were no significant changes to anxiety sensitivity. Results suggest that moderately anxious individuals self‐select a vigorous aerobic exercise intensity that results in improvements in state anxiety and affect to the same extent as static stretching of low intensity. Changes to anxiety sensitivity do not appear to explain these effects.