PLoS ONE (Jan 2013)

Fatigue shifts and scatters heart rate variability in elite endurance athletes.

  • Laurent Schmitt,
  • Jacques Regnard,
  • Maxime Desmarets,
  • Fréderic Mauny,
  • Laurent Mourot,
  • Jean-Pierre Fouillot,
  • Nicolas Coulmy,
  • Grégoire Millet

DOI
https://doi.org/10.1371/journal.pone.0071588
Journal volume & issue
Vol. 8, no. 8
p. e71588

Abstract

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PurposeThis longitudinal study aimed at comparing heart rate variability (HRV) in elite athletes identified either in 'fatigue' or in 'no-fatigue' state in 'real life' conditions.Methods57 elite Nordic-skiers were surveyed over 4 years. R-R intervals were recorded supine (SU) and standing (ST). A fatigue state was quoted with a validated questionnaire. A multilevel linear regression model was used to analyze relationships between heart rate (HR) and HRV descriptors [total spectral power (TP), power in low (LF) and high frequency (HF) ranges expressed in ms(2) and normalized units (nu)] and the status without and with fatigue. The variables not distributed normally were transformed by taking their common logarithm (log10).Results172 trials were identified as in a 'fatigue' and 891 as in 'no-fatigue' state. All supine HR and HRV parameters (Beta±SE) were significantly different (PConclusionHRV was significantly lower in 'fatigue' vs. 'no-fatigue' but accompanied with larger intra-individual variance of HRV parameters in 'fatigue'. The broader intra-individual variance of HRV parameters might encompass different changes from no-fatigue state, possibly reflecting different fatigue-induced alterations of HRV pattern.