Exercise training comprising of single 20-s cycle sprints does not provide a sufficient stimulus for improving maximal aerobic capacity in sedentary individuals

Sprint 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 . Thirty 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. Mean 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 x time interaction effect: P = 0.26). Although 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.