Heart rate-index estimates aerobic metabolism in professional soccer players.

OBJECTIVES

This study aimed at proposing a new heart rate (HR) method to track aerobic metabolism in soccer by: (i) validating a recently developed HR index (HR) in professional soccer players, (ii) comparing HR vs the most common HR parameters and (iii) testing the agreement between measured and estimated VO values using HR.

DESIGN

cross-sectional.

METHODS

184 professional soccer players performed a step incremental running test on a treadmill while VO and HR were recorded. HR was calculated (actual HR/resting HR) and its relationship with VO was compared with the relationships with the metabolism of actual HR, net HR, and % of HR reserve. Finally, HR was used to predict VO=((HR·6)-5)·3.5) and measured and estimated VO were compared by 2W RM-ANOVA and Bland-Altman analysis.

RESULTS

HR/VO relationship explained 85% of the variability in data, showing a higher performance than actual HR (77%) and similar values to the other parameters. Measured and estimated VO were not significantly different ≤14kmh, whereas at speeds ≥14kmh measured VO was higher than estimated VO. Finally, measured and estimated VO were highly correlated (R=0.85, p=0.000), and showed no significant bias (bias=-1.03, z=-0.69, precision=3.75mlkgmin).

CONCLUSIONS

We validated the HR/VO relationship in professional soccer players. HR showed better agreement with metabolism than actual HR and similar agreement to the other HR parameters. HR allowed to estimate VO, but at very high-intensity HR underestimated VO. Future studies should test this in real game conditions. HR could offer a time-efficient and easy-to-use "field" method to monitor aerobic metabolism in soccer.