When Moderate Becomes Unpleasant and Intense Is Manageable: Exercise Intensity and Duration Interact to Regulate Exercise Enjoyment and Changes in Affective Valence

Citation

Kinghorn DJ, Hutchinson M, Curry S, Zhang J & Vollaard NB (2026) When Moderate Becomes Unpleasant and Intense Is Manageable: Exercise Intensity and Duration Interact to Regulate Exercise Enjoyment and Changes in Affective Valence. Journal of Sport and Exercise Psychology, pp. 1-11. https://doi.org/10.1123/jsep.2025-0086

Abstract
Exercise at higher intensities has been hypothesized to lead to greater decreases in affective valence, negatively impacting exercise enjoyment and adherence. Thus, findings that high-intensity interval training and sprint interval training (SIT) may be enjoyed more than moderate-intensity continuous training appear paradoxical. The aim of the present study was to examine whether this can be explained by an Intensity × Duration interaction effect. Twenty-nine participants (18 women; mean [standard deviation] age: 24 [5] years, body mass index: 23.4 [3.2] kg/m2, VO2max: 39.5 [6.5] ml·kg−1·min−1) performed five cycling sessions involving either 30 min at 80%, 100%, or 110% of the ventilatory threshold (VT), SIT (22-min session including 4 × 30-s all-out sprints), or reduced-exertion high-intensity interval training (REHIT; 10-min session including 2 × 20-s all-out sprints). The decrease in affective valence during exercise was faster with higher intensities, but the brief duration of supramaximal sprints attenuated the absolute drop (no significant differences between REHIT, −0.7 [0.5]; 80% VT, −0.7 [0.5]; and 100% VT, −1.3 [0.6]; significantly greater decreases during SIT, −1.9 [0.6] and 110% VT, −3.0 [0.7]; both p < .01 vs. REHIT and 80% VT). REHIT involved lower exposure to reduced affect compared with the other trials (p < .001), and greater remembered enjoyment (physical activity enjoyment scale: 88 [16] compared with SIT, 71 [22], p < .001, and 110% VT, 73 [20], p = .003; no significance compared with 80% VT, 82 [18] or 100% VT, 76 [21]). Seventy-two percent of participants expressed a preference for REHIT. In conclusion, we provide evidence for an Intensity × Duration interaction effect for changes in affective valence during exercise. This explains the paradoxical finding that despite more rapid decreases in affective valence during exercise, high-intensity interval training/SIT can be enjoyed more than moderate-intensity continuous training.

Journal
Journal of Sport and Exercise Psychology