Physiological and Psychological Responses during Low-Volume High-Intensity Interval Training Sessions with Different Work-Recovery Durations

We compared physiological and psychological responses between low-volume high-intensity interval training (LV-HIIT) sessions with different work-recovery durations. Ten adult males performed two LV-HIIT sessions in a randomized, counter-balanced order. Specifically, 60/60 s LV-HIIT and 30/30 s LV-HIIT. Oxygen uptake (VO2), carbon dioxide output (VCO2), ventilation (VE), respiratory exchange ratio (RER), perceived exertion (RPE), and affect were assessed. During intervals, the VO2 (3.25 +/- 0.57 vs. 2.83 +/- 0.50 L/min), VCO2 (3.15 +/- 0.61 vs. 2.93 +/- 0.58 L/min), VE (108.59 +/- 27.39 vs. 94.28 +/- 24.98 L/min), and RPE (15.9 +/- 1.5 vs. 13.9 +/- 1.5) were higher (ps <= 0.01), while RER (0.98 +/- 0.05 vs. 1.03 +/- 0.03) and affect (-0.8 +/- 1.4 vs. 1.1 +/- 2.0) were lower (ps <= 0.007) in the 60/60 s LV-HIIT. During recovery periods, VO2 (1.85 +/- 0.27 vs. 2.38 +/- 0.46 L/min), VCO2 (2.15 +/- 0.35 vs. 2.44 +/- 0.45 L/min), and affect (0.6 +/- 1.7 vs. 1.7 +/- 1.8) were lower (ps <= 0.02), while RER (1.20 +/- 0.05 vs. 1.03 +/- 0.05; p < 0.001) was higher in the 60/60 s LV-HIIT. Shorter LV-HIIT (30 s) elicits lower physiological response and attenuated negative affect than longer LV-HIIT (60 s).