一种识别最大代谢稳态的“阶梯式递增”方案。

A "Step-Ramp-Step" Protocol to Identify the Maximal Metabolic Steady State.

机构信息

Faculty of Kinesiology, University of Calgary, Calgary, Alberta, CANADA.

Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, ITALY.

出版信息

Med Sci Sports Exerc. 2020 Sep;52(9):2011-2019. doi: 10.1249/MSS.0000000000002343.

DOI:10.1249/MSS.0000000000002343

PMID:32205678

Abstract

UNLABELLED

The oxygen uptake (V[Combining Dot Above]O2) at the respiratory compensation point (RCP) closely identifies with the maximal metabolic steady state. However, the power output (PO) at RCP cannot be determined from contemporary ramp-incremental exercise protocols.

PURPOSE

This study aimed to test the efficacy of a "step-ramp-step" (SRS) cycling protocol for estimating the PO at RCP and the validity of RCP as a maximal metabolic steady-state surrogate.

METHODS

Ten heathy volunteers (5 women; age: 30 ± 7 yr; V[Combining Dot Above]O2max: 54 ± 6 mL·kg·min) performed in the following series: a moderate step transition to 100 W (MOD), ramp (30 W·min), and after 30 min of recovery, step transition to ~50% POpeak (HVY). Ventilatory and gas exchange data from the ramp were used to identify the V[Combining Dot Above]O2 at lactate threshold (LT) and RCP. The PO at LT was determined by the linear regression of the V[Combining Dot Above]O2 versus PO relationship after adjusting ramp data by the difference between the ramp PO at the steady-state V[Combining Dot Above]O2 from MOD and 100 W. Linear regression between the V[Combining Dot Above]O2-PO values associated with LT and HVY provided, by extrapolation, the PO at RCP. Participants then performed 30-min constant-power tests at the SRS-estimated RCP and 5% above this PO.

RESULTS

All participants completed 30 min of constant-power exercise at the SRS-estimated RCP achieving steady-state V[Combining Dot Above]O2 of 3176 ± 595 mL·min that was not different (P = 0.80) from the ramp-identified RCP (3095 ± 570 mL·min) and highly consistent within participants (bias = -26 mL·min, r = 0.97, coefficient of variation = 2.3% ± 2.8%). At 5% above the SRS-estimated RCP, four participants could not complete 30 min and all, but two exhibited non-steady-state responses in blood lactate and V[Combining Dot Above]O2.

CONCLUSIONS

In healthy individuals cycling at their preferred cadence, the SRS protocol and the RCP are capable of accurately predicting the PO associated with maximal metabolic steady state.

摘要

未加说明

呼吸补偿点（RCP）处的耗氧量（V[Combining Dot Above]O2）与最大代谢稳态密切相关。然而，当代递增 ramp 运动方案无法确定 RCP 处的功率输出（PO）。

目的

本研究旨在测试“阶梯 ramp 阶梯”（SRS）自行车方案估算 RCP 处 PO 的功效，并验证 RCP 作为最大代谢稳态替代物的有效性。

方法

10 名健康志愿者（5 名女性；年龄：30 ± 7 岁；V[Combining Dot Above]O2max：54 ± 6 mL·kg·min）进行以下系列测试：适度向 100 W（MOD）过渡，然后递增 ramp（30 W·min），并在 30 分钟恢复期后，过渡至接近 50%POpeak（HVY）。ramp 期间的通气和气体交换数据用于确定乳酸阈（LT）和 RCP 处的 V[Combining Dot Above]O2。通过从 MOD 和 100 W 的 ramp PO 之间的差值调整 ramp 数据，对 V[Combining Dot Above]O2 与 PO 关系的线性回归确定 LT 处的 PO。LT 和 HVY 相关的 V[Combining Dot Above]O2-PO 值的线性回归通过外推提供了 RCP 处的 PO。参与者随后在 SRS 估算的 RCP 和高于此 PO5%的位置进行 30 分钟恒功率测试。

结果

所有参与者均在 SRS 估算的 RCP 处完成 30 分钟恒功率运动，达到 3176 ± 595 mL·min 的稳态 V[Combining Dot Above]O2，与 ramp 确定的 RCP（3095 ± 570 mL·min）无差异（P = 0.80），且参与者内高度一致（偏差=-26 mL·min，r = 0.97，变异系数=2.3%±2.8%）。在 SRS 估算的 RCP 之上 5%的位置，有 4 名参与者无法完成 30 分钟，且所有人（除 2 人外）均出现血乳酸和 V[Combining Dot Above]O2 的非稳态反应。