Core affective responses to light, moderate, and high intensity resistance exercise: a quasi-experimental study

Exercise has positive benefits to health, yet global inactivity levels remain high. Core affective experiences across aerobic exercise intensities have been shown to influence future exercise adherence, both positively and negatively. Yet, whether varying resistance exercise intensities exert similarly differential effects on core affect remains unclear. A total of 47 participants took part (60% males, 40% females) aged 20.60 years (SD = 1.57), with a median of two years’ experience in resistance exercise. A quasi-experimental, crossover design study was conducted, incorporating three relative resistance exercise intensity conditions. Conditions were anchored by Rating of Perceived Exertion/Repetitions in Reserve (RPE/RIR) prescription, and calculated via percentage estimates of 10-repetitions maximum, namely: 40% (light-intensity), 70% (moderate-intensity), and 100% (high-intensity). The primary outcomes measured during and up to 15 minutes after exercise were affective valence (perceived pleasure or displeasure) and felt arousal (perceived activation). A 3 (conditions) x 11 (timepoints) Repeated Measures Analysis of Variance revealed significant interaction effects for condition. Specifically, although all intensity prescriptions elicited a generalised positive effect on core affect, affective valence was significantly more positive during the light-intensity condition in comparison with both moderate and high-intensity conditions. In contrast, high-intensity resistance exercise induced temporary reductions in affective valence that reached a peak decline during the final sets of each exercise, but was followed by an affective rebound post-exercise. Overall, light-intensity exercise provided a more pleasant affective experience during resistance exercise, and may represent a less effortful, yet, health-enhancing form of physical activity. Based on the temporary reductions in affective valence during high-intensity exercise, we suggest pragmatism in prescribing individualised, tolerable, valence-preserving, resistance exercises.