Accuracy of a non‐exercise method using seismocardiography for the estimation of V̇O2peak in sub‐elite football players

Abstract

AbstractA non‐exercise method equation using seismocardiography for estimating V̇O2peak (SCG V̇O2peak) has previously been validated in healthy subjects. However, the performance of the SCG V̇O2peak within a trained population is unknown, and the ability of the model to detect changes over time is not well elucidated. Forty‐seven sub‐elite football players were tested at the start of pre‐season (SPS) and 36 players completed a test after eight weeks at the end of the pre‐season (EPS). Testing included an SCG V̇O2peak estimation at rest and a graded cardiopulmonary exercise test (CPET) on a treadmill for determination of V̇O2peak. Agreement between SCG V̇O2peak and CPET V̇O2peak showed a large underestimation at SPS (bias ± 95% CI: −9.9 ± 1.8, 95% Limits of Agreement: 2.2 to −22.0 mL·min−1 kg−1). At EPS no interaction (p = 0.3590) but a main effect of time (p < 0.0001) and methods (p < 0.0001) was observed between SCG and CPET V̇O2peak. No correlation in V̇O2peak changes was observed between SCG and CPET (r = −20.0, p = 0.2484) but a fair agreement in classifying the correct directional change in V̇O2peak with the SCG method was found (Cohen's κ coefficient = 0.28 ± 0.25). Overall, the SCG V̇O2peak method lacks accuracy and despite being able to estimate group changes, it was incapable of detecting individual changes in V̇O2peak following a pre‐season period in sub‐elite football players. The SCG algorithm needs to be further adjusted and the accuracy and precision improved for the method to be applicable for use within a trained population.