Burning for a warm glow: The impact of acute exercise on mood and prosocial behaviour

Social disconnection represents a growing public health concern, closely linked to diminished wellbeing and quality of life. Group-based exercise programmes are often promoted as contexts that increase social connectedness and psychological health. While acute exercise is known to improve mood and cognitive functioning, it remains unclear whether exercise itself, independent of its social context, can directly promote prosocial behaviour. Guided by Broaden-and-Build Theory and psychophysiological models of mood regulation, this preregistered experiment examined whether a single session of moderate-intensity exercise influences observed prosocial behaviour and whether changes in mood mediate this relationship. A total of 138 adults completed baseline mood assessments before viewing a 20-minute television segment, during which participants in the experimental condition cycled at moderate intensity, while those in the control condition remained seated on exercise bikes. Following the intervention, participants completed post-test mood measures and engaged in incentivised social decision-making tasks. To control for expectancy effects, all participants subsequently completed a brief exercise session. Exercise did not produce a direct increase in prosocial behaviour. However, an indirect effect was observed via changes in self-reported mood, with increased vigour predicting greater prosocial behaviour. This indicates that acute exercise may be more effective in promoting prosocial behaviour among individuals who experience improved, energised mood in response to exercise. These findings suggest that individual emotional responses to exercise may be an important consideration for social prescribing initiatives seeking to support social connectedness.