Background/Aim: Reduced-exertion high-intensity interval training (REHIT) is a genuinely

PurposeSprint interval training (SIT) provides a potent stimulus for improving maximal aerobic capacity (), which is among the strongest markers for future cardiovascular health and premature mortality. Cycling-based SIT protocols involving six or more ‘all-out’ 30-s Wingate sprints per training session improve , but we have recently demonstrated that similar improvements in can be achieved with as few as two 20-s sprints. This suggests that the volume of sprint exercise has limited influence on subsequent training adaptations. Therefore, the aim of the present study was to examine whether a single 20-s cycle sprint per training session can provide a sufficient stimulus for improving .MethodsThirty sedentary or recreationally active participants (10 men/20 women; mean ± SD age: 24 ± 6 years, BMI: 22.6 ± 4.0 kg m−2, : 33 ± 7 mL kg−1 min−1) were randomised to a training group or a no-intervention control group. Training involved three exercise sessions per week for 4 weeks, consisting of a single 20-s Wingate sprint (no warm-up or cool-down). was determined prior to training and 3 days following the final training session.ResultsMean did not significantly change in the training group (2.15 ± 0.62 vs. 2.22 ± 0.64 L min−1) or the control group (2.07 ± 0.69 vs. 2.08 ± 0.68 L min−1; effect of time: P = 0.17; group × time interaction effect: P = 0.26).ConclusionAlthough we have previously demonstrated that regularly performing two repeated 20-s ‘all-out’ cycle sprints provides a sufficient training stimulus for a robust increase in , our present study suggests that this is not the case when training sessions are limited to a single sprint.