To vary or not to vary? Interpreting HRV in soccer players

Abstract

Within-measure variability Heart rate variability (HRV) is becoming one of the most widely used physiological variables to quantify the stress and recovery of soccer players. At rest, cardiac vagal modulation can be inferred by the logarithm of the root mean square of successive R-R interval differences (lnRMSSD), and it has been shown that higher values are related to higher training status (Proietti et al., 2017). Low variability within a measure relative to baseline may reflect inadequate recovery from previous exertion (Bricout et al., 2010; Muñoz-López, in press) or heightened stress. Reduced lnRMSSD may also be observed near or on match-day due to pre-competitive arousal (Ayuso-Moreno et al., im press). Thus, high variability between consecutive RR intervals within a measure, resulting in a high single day lnRMSSD measure is generally good.