Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.
Int J Sports Physiol Perform. 2023 Oct 28;19(1):84-87. doi: 10.1123/ijspp.2023-0260. Print 2024 Jan 1.
Although running traditionally relies on critical speed (CS) as an indicator of critical intensity, portable inertial measurement units offer a potential solution for estimating running mechanical power to assess critical power (CP) in runners. The purpose of this study was to determine whether CS and CP differ when assessed using the Stryd device, a portable inertial measurement unit, and if 2 running bouts are sufficient to determine CS and CP.
On an outdoor running track, 10 trained runners (V˙O2max, 59.0 [4.2] mL·kg-1·min-1) performed 3 running time trials (TT) between 1200 and 4400 m on separate days. CS and CP were derived from 2-parameter hyperbolic speed-time and power-time models, respectively, using 2 (CS2TT and CP2TT) and 3 (CS3TT and CP3TT) TTs. Subsequently, runners performed constant-intensity running for 800 m at their calculated CS3TT and CP3TT.
Running at the calculated CS3TT speed (3.88 [0.44] m·s-1) elicited an average Stryd running power (271 [28] W) not different from the calculated CP3TT (270 [28]; P = .940; d = 0.02), with excellent agreement between the 2 values (intraclass correlation coefficient = .980). The CS2TT (3.97 [0.42] m·s-1) was not higher than CS3TT (3.89 [0.44] m·s-1; P = .178; d = 0.46); however, CP2TT (278 [29] W) was greater than CP3TT (P = .041; d = 0.75).
The running intensities at CS and CP were similar, supporting the use of running power (Stryd) as a metric of aerobic fitness and exercise prescription, and 2 trials provided a reasonable, albeit higher, estimate of CS and CP.
虽然传统上跑步依赖临界速度（CS）作为临界强度的指标，但便携式惯性测量单元提供了一种潜在的解决方案，可以估计跑步机械功率，以评估跑步者的临界功率（CP）。本研究的目的是确定使用便携式惯性测量单元 Stryd 设备评估 CS 和 CP 是否不同，以及进行 2 次跑步试验是否足以确定 CS 和 CP。
在户外跑道上，10 名训练有素的跑步者（最大摄氧量为 59.0 [4.2] mL·kg-1·min-1）在不同的日子里进行了 3 次跑步时间试验（TT），跑步距离分别为 1200 米至 4400 米。CS 和 CP 分别来自于双参数双曲线速度-时间和功率-时间模型，使用 2 次（CS2TT 和 CP2TT）和 3 次（CS3TT 和 CP3TT）TT。随后，跑步者以计算得出的 CS3TT 速度（3.88 [0.44] m·s-1）进行 800 m 的恒强度跑步。
以计算得出的 CS3TT 速度（3.88 [0.44] m·s-1）进行跑步时，Stryd 测量的平均跑步功率（271 [28] W）与计算得出的 CP3TT （270 [28]；P =.940；d = 0.02）没有差异，2 个值之间具有极好的一致性（组内相关系数 =.980）。CS2TT（3.97 [0.42] m·s-1）并不高于 CS3TT（3.89 [0.44] m·s-1；P =.178；d = 0.46）；然而，CP2TT（278 [29] W）大于 CP3TT（P =.041；d = 0.75）。
CS 和 CP 的跑步强度相似，支持使用跑步功率（Stryd）作为有氧健身和运动处方的指标，并且 2 次试验提供了 CS 和 CP 的合理（尽管较高）估计值。
