Are HIIT and MICT sex(y)? Exploring sex differences in in-task affect over a progressive 2-week exercise intervention


Physiological studies have suggested differences in fatigue resistance, metabolic recovery, and performance adaptation between females and males during high-intensity interval training (HIIT) and moderate intensity continuous training (MICT) protocols. However, there is a lack of research examining potential biological sex differences in psychological constructs during such exercise modalities. The purpose of this study was to determine whether there is a difference in in-task affective responses dependent on biological sex in both HIIT and MICT exercise protocols. Ninety-nine adults that were low active were randomized into a supervised HIIT or MICT progressive exercise program for 10 sessions over 2 weeks. In-task affect was measured on sessions 1, 6, and 10 of the intervention using the Feeling Scale and the peak negative value from all days was calculated for comparison. Two-tailed independent samples t-tests showed no significant differences in peak negative in-task affect between females and males for both HIIT [t(44) = .755, p = .45, d = .25] and MICT [t(48) = .791, p = .43, d = .24] exercise conditions, suggesting that both exercise modalities are well tolerated regardless of biological sex. Research beyond sex is needed to determine whether differences in in-task affect exist depending on individuals' gender and/or sexual identity, and whether sex, gender, and sexual identity differences exist for other psychological constructs of interest.

Acknowledgments: The authors would like to acknowledge that this study was completed on the unceded, ancestral lands of the Silkh nation.