Validity of the Stryd Power Meter in Measuring Running Parameters at Submaximal Speeds.

Frank Imbach,Romain Chailan,Robin Candau,Stephane Perrey

doi:10.3390/sports8070103

Frank Imbach, Romain Chailan + Show 2 more

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https://doi.org/10.3390/sports8070103

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Journal: Sports	Publication Date: Jul 20, 2020
Citations: 39	License type: CC BY 4.0

Affiliation: University of Montpellier, École des Mines d'Alès

Abstract

This study assessed the Stryd running power meter validity at sub-maximal speeds (8 to 19 km/h). Six recreational runners performed an incremental indoor running test. Power output (PO), ground contact time (GCT) and leg spring stiffness (LSS) were compared to reference measures recorded by portable metabolic analyser, force platforms and motion capture system. A Bayesian framework was conducted for systems validity and comparisons. We observed strong and positive linear relationships between Stryd PO and oxygen consumption (, ), and between Stryd PO and external mechanical power (, ). Stryd power meter underestimated PO () whereas GCT and LSS values did not show any significant differences with the reference measures (, , respectively). We conclude that the Stryd power meter provides valid measures of GCT and LSS but underestimates the absolute values of PO.

Highlights

The last decade was marked by technological improvements in wearable sport devices to quantify the exercise features in ecological conditions
By comparing the Cm with the increase of speed, we observed a moderate negative linear relationship for all participants (R2 = 0.66, [0.60, 0.71] 95% credible intervals (CI)). Both speed and subject have shown an effect on the Cm measure with an extreme evidence (BF10 > 100)
Bayes factor reported an extreme evidence in favour of the null hypothesis (BF10 = 0.008)

Summary

Introduction

The last decade was marked by technological improvements in wearable sport devices to quantify the exercise features in ecological conditions. Endurance runners showed a large interest for non-differential global positioning systems (GPS), stride sensors and heart rate monitors integrated in sport watches. Such devices allow them to quantify their exercise and to program their training protocols. Parameters of importance are volume and intensity, commonly estimated by physical measures (e.g., distance covered, elevation, speed) and physiological markers (i.e. indexes mostly assessed from exercise heart rate). Despite some validity and reliability studies carried out in laboratory at sub-maximal speeds [2,3], GPS measures are unsuitable in indoor conditions.

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