Application of V?o2 to the Critical Power Model to Derive the Critical V?o2

Succi, PJ, Dinyer, TK, Byrd, MT, Voskuil, CC, and Bergstrom, HC. Application of V?o(2) to the critical power model to derive the critical V?o(2). J Strength Cond Res 36(12): 3374-3380, 2022-The purposes of this study were to (a) determine whether the critical power (CP) model could be applied to V?o(2) to estimate the critical V?o(2) (CV?o(2)) and (b) to compare the CV?o(2) with the V?o(2) at CP (V?o(2)CP), the ventilatory threshold (VT), respiratory compensation point (RCP), and the CV?o(2) without the V?o(2) slow component (CV?o(2)slow). Nine subjects performed a graded exercise test to exhaustion to determine V?o(2)peak, VT, and RCP. The subjects performed 4 randomized, constant power output work bouts to exhaustion. The time to exhaustion (T-Lim), the total work (W-Lim), and the total volume of oxygen consumed with (TV?o(2)) and without the slow component (TV?o(2)slow) were recorded during each trial. The linear regressions of the TV?o(2) vs. T-Lim, TV?o(2)slow vs. T-Lim, and W-Lim vs. T-Lim relationship were performed to derive the CV?o(2), CV?o(2)slow, and CP, respectively. A 1-way repeated-measures analysis of variance (p <= 0.05) with follow-up Sidak-Bonferroni corrected pairwise comparisons indicated that CV?o(2) (42.49 +/- 3.22 ml center dot kg(-1)center dot min(-1)) was greater than VT (30.80 +/- 4.66 ml center dot kg(-1)center dot min(-1); p < 0.001), RCP (36.74 +/- 4.49 ml center dot kg(-1)center dot min(-1); p = 0.001), V?o(2)CP (36.76 +/- 4.31 ml center dot kg(-1)center dot min(-1); p < 0.001), and CV?o(2)slow (38.26 +/- 2.43 ml center dot kg(-1)center dot min(-1); p < 0.001). However, CV?o(2)slow was not different than V?o(2)CP (p = 0.140) or RCP (p = 0.235). Thus, the CP model can be applied to V?o(2) to derive the CV?o(2) and theoretically is the highest metabolic steady state that can be maintained for an extended period without fatigue. Furthermore, the ability of the CV?o(2) to quantify the metabolic cost of exercise and the inefficiency associated with the V?o(2) slow component may provide a valuable tool for researchers and coaches to examine endurance exercise.