Micheli Lorenzo, Teso Massimo, Guluzade Nasimi A, Rizzo Matteo, Ferri Marini Carlo, Lucertini Francesco, Keir Daniel A, Pogliaghi Silvia
School of Kinesiology, The University of Western Ontario, London, ON, Canada.
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
Appl Physiol Nutr Metab. 2025 Jan 1;50:1-10. doi: 10.1139/apnm-2024-0042. Epub 2024 Sep 4.
We investigated whether pedal cadence (60 vs. 100 rpm) affects oxygen uptake (V̇O) and power output (PO) at two indexes of the heavy-to-severe-intensity domain boundary (i.e., critical power (CP) and respiratory compensation point (RCP)) and their correspondence. Fourteen adults (7 females, 23 ± 2 years) cycled at 60 and 100 rpm during: (i) a "step-ramp-step" protocol to identify V̇O and PO at RCP; (ii) 4-5 exhaustive constant-PO bouts for CP identification; and (iii) a constant-power bout at CP to identify V̇O at CP. Separate two-way repeated measures Analysis of variance assessed whether V̇O and PO were affected by index (CP vs. RCP) and cadence (60 vs. 100 rpm). The V̇O was not affected by index (mean difference (MD) = 73 ± 197 mL·min; = 0.136) but there was an index × cadence interaction ( = 0.014), such that V̇O was higher at 100 versus 60 rpm for CP (MD = 142 ± 169 mL·min; = 0.008), but not RCP ( = 0526). The PO was affected by cadence (MD = 13 ± 9 W; < 0.001) and index (MD = 8 ± 11 W; = 0.016), with no cadence × index interaction ( = 0.168). The systematic bias in PO confirms cadence-specificity of CP and RCP. The relationship between these indexes and their change in unison in PO suggests a mechanistic link between these two heavy-to-severe domain boundary candidates.
我们研究了踏板踏频（60与100转/分钟）在重到极量强度域边界的两个指标（即临界功率（CP）和呼吸补偿点（RCP））及其对应关系下，是否会影响摄氧量（V̇O）和功率输出（PO）。14名成年人（7名女性，23±2岁）在以下过程中以60和100转/分钟的踏频进行骑行：（i）一个“阶梯-斜坡-阶梯”方案，以确定RCP时的V̇O和PO；（ii）4-5次竭尽全力的恒定功率骑行，用于确定CP；以及（iii）一次在CP时的恒定功率骑行，以确定CP时的V̇O。独立的双向重复测量方差分析评估了V̇O和PO是否受指标（CP与RCP）和踏频（60与100转/分钟）的影响。V̇O不受指标影响（平均差异（MD）=73±197毫升·分钟；P = 0.136），但存在指标×踏频交互作用（P = 0.014），即对于CP，100转/分钟时的V̇O高于60转/分钟（MD = 142±169毫升·分钟；P = 0.008），而对于RCP则不然（P = 0.526）。PO受踏频（MD = 13±9瓦；P < 0.001）和指标（MD = 8±11瓦；P = 0.016）影响，不存在踏频×指标交互作用（P = 0.168）。PO中的系统偏差证实了CP和RCP的踏频特异性。这些指标之间的关系以及它们在PO中一致变化表明这两个重到极量域边界候选指标之间存在机制联系。
