Exercise Training Comprising of Single 20‑s Cycle Sprints Does Not Provide a Sufficient Stimulus for Improving Maximal Aerobic Capacity in Sedentary Individuals

Purpose Sprint interval training (SIT) provides a\ud potent stimulus for improving maximal aerobic capacity\ud (V˙ O2max ), which is among the strongest markers for\ud future cardiovascular health and premature mortality.\ud Cycling-based SIT protocols involving six or more ‘all-out’\ud 30-s Wingate sprints per training session improve V˙ O2max ,\ud but we have recently demonstrated that similar improvements\ud in V˙ O2max can be achieved with as few as two 20-s\ud sprints. This suggests that the volume of sprint exercise\ud has limited influence on subsequent training adaptations.\ud Therefore, the aim of the present study was to examine\ud whether a single 20-s cycle sprint per training session can\ud provide a sufficient stimulus for improving V˙ O2max.\ud Methods Thirty sedentary or recreationally active participants(10 men/20 women; mean ± SD age: 24 ± 6 years,\ud BMI: 22.6 ± 4.0 kg m−2, V˙ O2max: 33 ± 7 mL kg−1 min−1)\ud were randomised to a training group or a no-intervention\ud control group. Training involved three exercise sessions\ud per week for 4 weeks, consisting of a single 20-s Wingate\ud sprint (no warm-up or cool-down). V˙ O2max was determined\ud prior to training and 3 days following the final training\ud session.Results Mean V˙ O2max did not significantly change in the\ud training group (2.15 ± 0.62 vs. 2.22 ± 0.64 L min−1) or\ud the control group (2.07 ± 0.69 vs. 2.08 ± 0.68 L min−1;\ud effect of time: P = 0.17; group × time interaction effect:\ud P = 0.26).\ud Conclusion Although we have previously demonstrated\ud that regularly performing two repeated 20-s ‘all-out’ cycle\ud sprints provides a sufficient training stimulus for a robust\ud increase in V˙ O2max, our present study suggests that this is not the case when training sessions are limited to a single sprint