Prediction of power output at different running velocities through the two-point method with the Stryd™ power meter

Abstract

BackgroundThe force- and power-velocity (F–V and P–V, respectively) relationships have been extensively studied in recent years. However, its use and application in endurance running events is limited. Research questionThis study aimed to determine if the P–V relationship in endurance runners fits a linear model when running at submaximal velocities, as well as to examine the feasibility of the “two-point method” for estimating power values at different running velocities. MethodsEighteen endurance runners performed, on a motorized treadmill, an incremental running protocol to exhaustion. Power output was obtained at each stage with the Stryd™ power meter. The P–V relationship was determined from a multiple-point method (10, 12, 14, and 17 km·h−1) as well as from three two-point methods based on proximal (10 and 12 km·h−1), intermediate (10 and 14 km·h−1) and distal (10 and 17 km·h−1) velocities. ResultsThe P–V relationship was highly linear ( r = 0.999). The ANOVAs revealed significant, although generally trivial (effect size < 0.20), differences between measured and estimated power values at all the velocities tested. Very high correlations ( r = 0.92) were observed between measured and estimated power values from the 4 methods, while only the multiple-point method ( r2 = 0.091) and two-point method distal ( r2 = 0.092) did not show heteroscedasticity of the error. SignificanceThe two-point method based on distant velocities (i.e., 10 and 17 km·h−1) is able to provide power output with the same accuracy than the multiple-point method. Therefore, since the two-point method is quicker and less prone to fatigue, we recommend the assessment of power output under only two distant velocities to obtain an accurate estimation of power under a wide range of submaximal running velocities.