Mindfulness Interventions During Exercise: More Pleasant Core Affective Feelings for Regular Exercisers but Not for the Physically Inactive

This study aimed to investigate the effectiveness of mindfulness in improving affect during moderate-intensity exercise and to test the hypothesis that this intervention is particularly beneficial for those who are already sufficiently active. Two groups of sufficiently and insufficiently active participants were recruited to complete a 20-min moderate-intensity exercise (based on 55%-65% of heart rate reserve) on treadmill in three different experimental conditions (mindfulness, attention distraction, and no-intervention control) in a randomized order. Core affective valence was measured repeatedly during exercise. Linear mixed-effects modeling and subsequent Tukey post hoc comparisons revealed that more positive affective responses occurred in the mindfulness condition than in attention distraction and control conditions, but only among those who reported sufficient physical activity in their daily lives. We also found that participants in the insufficiently active group experienced more pleasant feelings in the attention distraction condition than in the control condition. Additional exploratory analysis suggested that all participants reported a more positive forecasted affect for exercising in the future in mindfulness and attention distraction conditions, whereas only the sufficiently active group reported greater postexercise enjoyment after mindfulness condition. We interpret these findings as evidence that nonregular exercisers should be advised to divert their attention from their bodily sensations during moderate-intensity physical activity rather than to be mindful, which is more appropriate for those who are already used to regular exercise.