The Validity and Reliability of a Tire Pressure-Based Power Meter for Indoor Cycling.

Nicholas J Fiolo,Wei-Han Chen,Philip X Fuchs,Tzyy-Yuang Shiang,Hai-Ying Lu,Chia-Hsiang Chen

doi:10.3390/s21186117

Abstract

The purpose of this study was to evaluate the validity and reliability of a tire pressure sensor (TPS) cycling power meter against a gold standard (SRM) during indoor cycling. Twelve recreationally active participants completed eight trials of 90 s of cycling at different pedaling and gearing combinations on an indoor hybrid roller. Power output (PO) was simultaneously calculated via TPS and SRM. The analysis compared the paired 1 s PO and 1 min average PO per trial between devices. Agreement was assessed by correlation, linear regression, inferential statistics, effect size, and Bland–Altman LoA. Reliability was assessed by ICC and CV comparison. TPS showed near-perfect correlation with SRM in 1 s (rs = 0.97, p < 0.001) and 1-min data (rs = 0.99, p < 0.001). Differences in paired 1 s data were statistically significant (p = 0.04), but of a trivial magnitude (d = 0.05). There was no significant main effect for device (F(1,9) = 0.05, p = 0.83, = 0.97) in 1 min data and no statistical differences between devices by trial in post hoc analysis (p < 0.01–0.98; d < 0.01–0.93). Bias and LoA were −0.21 ± 16.77 W for the 1 min data. Mean TPS bias ranged from 3.37% to 7.81% of the measured SRM mean PO per trial. Linear regression SEE was 7.55 W for 1 min TPS prediction of SRM. ICC3,1 across trials was 0.96. No statistical difference (p = 0.09–0.11) in TPS CV (3.6–5.0%) and SRM CV (4.3–4.7%). The TPS is a valid and reliable power meter for estimating average indoor PO for time periods equal to or greater than 1 min and may have acceptable sensitivity to detect changes under less stringent criteria (±5%).

Highlights

Accurate and systematic quantification of exercise intensity is an integral component to monitor and prescribe exercise [1] for both athletic [2] and health-related goals [3].Exercise intensity can be broadly dichotomized into internal, relating to an individual’s specific acute stress response, and external, independent of the individual’s response [1]
Analysis revealed a statistically significant relationship between the two devices, rs = 0.97, 95% confidence p limits (95% CL) [0.97, 0.97], p < 0.001, n = 3779
The Wilcoxon signed-rank test indicated a statistically significant difference (p < 0.001) in median power output (PO) between tire pressure sensor (TPS)

Summary

Introduction

Accurate and systematic quantification of exercise intensity is an integral component to monitor and prescribe exercise [1] for both athletic [2] and health-related goals [3]. Exercise intensity can be broadly dichotomized into internal, relating to an individual’s specific acute stress response (e.g., heart rate), and external, independent of the individual’s response (e.g., average running speed) [1]. The individual relationship between internal and external intensity can be made to allow for a more complete evaluation of the dose of exercise and the consequential responses of physiological and performance changes. External intensity in cycling can be quantified as power output (PO) and measured with a cycling-specific power meter. Unlike heart rate, which can lag effort, or speed, which is influenced by terrain and wind, PO is an objective way to assess the instantaneous cycling intensity. PO can be linked to the physiological- (e.g., VO2max) [4] or performance-based (e.g., critical power) [5]

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Discussion

Conclusion