Morning Heart Rate Variability as an Indication of Fatigue Status in Badminton Players during a Training Camp.

Taro Iizuka,Yoriko Atomi,Nao Ohiwa,Tomoaki Atomi,Miho Shimizu

doi:10.3390/sports8110147

Abstract

This study aimed to clarify whether changes in the fatigue status of elite athletes during a precompetition period could be evaluated using morning heart rate variability (HRV) indices. Eight Japanese National Badminton Team players (age, 23.0 ± 2.8 years) participated in this study. HRV and subjective fatigue were measured during the first (days 1–4: Phase 1) and the second half (days 5–8: Phase 2) of an 8-day national team training camp. The global and parasympathetic HRV indices were as follows: standard deviation of all R-R intervals (SDNN) (Phase 1, 87.5 ms; Phase 2, 104.3 ms; p < 0.05), root mean square of the successive R-R interval differences (RMSSD) (Phase 1, 66.6 ms; Phase 2, 103.6 ms; p < 0.05), and high-frequency component power (HF) (Phase 1, 1412.0 ms2; Phase 2, 3318.5 ms2; p < 0.05). All the aforementioned indices increased significantly from Phase 1 to Phase 2. Significant correlations were observed between the change in subjective fatigue and changes in SDNN, RMSSD, and HF (ρ = −0.80, p = 0.017; ρ = −0.77, p = 0.027; and ρ = −0.80, p = 0.017, respectively). Measuring morning HRV indices may be effective for objectively evaluating changes in the fatigue status of elite athletes during a precompetition period.

Highlights

Excessive training during a precompetition period can induce fatigue accumulation, which may lead to impaired performance in subsequent competitions
The purpose of this study was to clarify whether the change in the fatigue status of elite athletes athletes during a precompetition period could be objectively evaluated by measuring the heart rate variability (HRV) indices
We demonstrated that the changes in HRV indices, such as standard deviation of all R-R intervals (SDNN), RMSSD, and high-frequency component power (HF), significantly

Summary

Introduction

Excessive training during a precompetition period can induce fatigue accumulation, which may lead to impaired performance in subsequent competitions. During the precompetition period, training load should be adequately controlled to ensure that fatigue is reduced when athletes participate in a competition [1]. Establishing a tool to objectively monitor how athletes respond to training would be necessary to guide training to optimize their performance, as their response to training may vary [2,3]. Previous studies have shown that monitoring the HRV to evaluate the cardiac parasympathetic nervous activity alone or in combination with the sympathetic nervous activity is effective for objectively monitoring the athletes’ fatigue status [5,6,7,8]. Monitoring individual HRV may provide an objective measure to evaluate changes in the athlete’s fatigue status during the precompetition period

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Results

Conclusion