School of Exercise & Nutritional Sciences, San Diego State University, San Diego, United States.
School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom of Great Britain and Northern Ireland.
Int J Sports Med. 2019 Sep;40(10):631-638. doi: 10.1055/a-0946-1974. Epub 2019 Jul 31.
The asymptote of the hyperbolic power-duration relationship, critical power (CP), demarcates sustainable from non-sustainable exercise. CP is a salient parameter within the theoretical framework determining exercise tolerance. However, measuring CP is time consuming - typically 4 constant-power exercise tests to intolerance, or a 3-min all-out sprint is required.To determine whether 30 s of maximal isokinetic cycling, immediately following the limit of tolerance, approximates CP.Fifteen participants (7 women, 8 men, 23±5 yr, 71±12 kg, V̇O 4.39±1.04 L·min; 61±9 mL·kg·min) completed 4 constant supra-CP exercise tests to intolerance. Each test was followed immediately by a 30 s maximal isokinetic effort at 80 rpm. Mean isokinetic power was compared to the known CP.Mean±SD CP was 159±47 W (CI 133, 185 W). Maximal isokinetic power immediately following intolerance was greater (0.05) than CP in all but one comparison (181±51 vs. 159±47 W; 0.07). However, this closest estimation, following the longest duration constant-power test, resulted in 21 W of mean bias and wide limits of agreement (±84 W).Isokinetic power measured immediately following intolerance consistently overestimated critical power. Thus, an adjunct of 30 s maximal isokinetic cycling immediately following the limit of tolerance does not approximate critical power.
双曲功率-时间关系的渐近线，即临界功率 (CP)，将可持续性和非可持续性运动区分开来。CP 是决定运动耐力的理论框架中的一个重要参数。然而，测量 CP 很耗时——通常需要进行 4 次恒功率运动测试直至不耐受，或进行 3 分钟全力冲刺。本研究旨在确定在达到耐受极限后立即进行 30 秒最大等速自行车运动是否可以近似 CP。15 名参与者（7 名女性，8 名男性，23±5 岁，71±12kg，V̇O 4.39±1.04L·min；61±9mL·kg·min）完成了 4 次超 CP 的恒功率运动至不耐受。每次测试后立即进行 30 秒最大等速 80rpm 运动。比较平均等速功率与已知 CP。平均±SD CP 为 159±47W（CI 133，185W）。在所有但一次比较中（181±51 vs. 159±47W；0.07），不耐受后立即进行的最大等速功率均高于 CP。然而，在最长持续时间恒功率测试后进行的最接近估计，导致平均偏差为 21W，一致性界限较宽（±84W）。在不耐受后立即测量的等速功率始终高估了临界功率。因此，在耐受极限后立即进行 30 秒最大等速自行车运动不能近似 CP。
