Affective Responses to Repeated Endurance Training Sessions with Different Intensities: A Randomized Trial

The purpose was to examine differences in affective responses to repeated sessions of endurance training with different intensities in healthy adults. Thirty young, healthy, and recreationally physically active adults (50% women, age 24.4 ± 6.0 years, VO_2max 48.6 ± 7.4 ml^-1·kg^-1·min^-1, BMI 23.5 ± 2.4 kg·m²) performed a VO_2max test. They were randomized to four sessions of either high intensity sprint interval training (SPRINT, n=10, 5 · 30-sec at >95 of HR_peak, 4-min recovery between intervals), high intensity aerobic interval training (HAIT, n=10, 4 · 4-min at ~90% of HR_peak, 4-min recovery between intervals) or moderate intensity continuous training (MIT, n=10, 50-min at ~75% HR_peak). Assessment during and after each session included HR, La^-, Borg ratings of perceived exertion (RPE), affective state (positive/negative), valence (pleasure/displeasure), arousal (calmness/excitement), tension, irritation, pain, exhaustion, satisfaction, and motivation. HR, La^- and Borg RPE were higher in SPRINT and HAIT compared to MIT (p < 0.001), no differences between SPRINT and HAIT. Displeasure and arousal were greater in SPRINT compared to HAIT (p < 0.05) and MIT (p < 0.001). Within each session, between-group effects showed that SPRINT differed from HAIT and MIT on valence (p < 0.01) and arousal (p < 0.01), and MIT differed from HAIT and SPRINT on La^- (p < 0.001) and HR (p < 0.001). In conclusion, repeated sessions of HAIT produced similar physiological responses as SPRINT, and similar affective responses as MIT.