BACKGROUND: Minimal workload to elicit peak O2 consumption (PminV̇O2peak) is accepted as sufficient exercise intensity to improve maximal O2 consumption (V̇O2max), and stroke volume (SV) is the most important component of the V̇O2max. The aim of the study was to examine whether cyclists’ maximal SV responses (SVmax) closely related to PminV̇O2peak, or not.
METHODS: Ventilatory threshold (VT) was measured by incremental tests. Then, constant-load verifications were performed to reveal the V̇O2max. The SVmax was analysed by constant-load exercises performed in the range of 40% and 100% of V̇O2max. Cyclists’ critical power (CP) was estimated based on the data obtained from four constant-load exhaustive tests. The PminV̇O2peak was accepted as the first work rate to elicit 5% closer V̇O2 responses to V̇O2max were attained. After repeated-measures analyses, possible significant differences investigated by LSD, and correlations were analysed by Pearson r.
RESULTS: The CP means were significantly lower than the PminV̇O2peak (295.4±40.2 W vs. 306.7±49 W; P<0.05). Fractional usages of V̇O2max belonging to the CP and PminV̇O2peak corresponded to 92% and 96% of V̇O2max, respectively. Moreover, PminV̇O2peak was greater than the power output at SVmax (P-SVmax) (214.1±60 W; P<0.05). There were weak correlations between P-SVmax and PminV̇O2peak (r: 0.30), P-SVmax and CP (r: 0.24); however, there were moderate correlations between SVmax and PminV̇O2peak (r: 0.64), SVmax and the CP (r: 0.66).
CONCLUSIONS: In conclusion, a greater value of SVmax may cause a significant performance gain by decreasing the gap between P-V̇O2max and PminV̇O2peak.