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
potent stimulus for improving maximal aerobic capacity
(V˙ O2max ), 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 V˙ O2max ,
but we have recently demonstrated that similar improvements
in V˙ O2max 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 V˙ O2max.
Methods Thirty sedentary or recreationally active participants(10 men/20 women; mean ± SD age: 24 ± 6 years,
BMI: 22.6 ± 4.0 kg m−2, V˙ O2max: 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). V˙ O2max was determined
prior to training and 3 days following the final training
session.Results Mean V˙ O2max 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).
Conclusion 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 V˙ O2max, our present study suggests that this is not the case when training sessions are limited to a single sprint.