Comprehensive assessment of heart rate variability, blood pressure, sleep quality, and anxiety in athletes with persistent fatigue

Abstract

Purpose. To provide a comprehensive assessment of heart rate variability, arterial blood pressure, sleep disorders, and anxiety in athletes with persistent fatigue.

Material & Methods. In total, 52 track and field athletes participated in the study. We divided them into groups according to their scores on the Fatigue Assessment Scale (FAS): the main group consisted of 11 athletes with scores of 22 points or higher, while the control group comprised the participants with scores below this threshold. There were no significant differences between groups in age, sex, training intensity, or representation in athletics disciplines. All study participants underwent assessment with the WHO-5 Well-Being Index, the Athens Insomnia Scale (AIS), the Epworth Sleepiness Scale (ESS), and the Hospital Anxiety and Depression Scale (HADS). We measured heart rate variability using the Cardio+ monitor during a 4-6 minute recording period.

Results. The findings showed that athletes with fatigue lasting more than two weeks demonstrated lower well-being, sleep disturbances, and higher levels of anxiety (p<0.001). The strongest correlation was observed between FAS scores and WHO-5 well-being (r=–0.902, p<0.001). Weaker correlations were observed between FAS scores and insomnia (AIS, r=0.691, p<0.001) and daytime sleepiness (ESS, r=0.684, p<0.001). No correlation between fatigue and anxiety was detected in the main group (r=0.340, p=0.306), and the overall correlation across all participants was weak (r=0.431, p<0.001). This indicates that anxiety is a distinct symptom, which, although more common in persistent fatigue, may have an independent significance, thus requiring a comprehensive approach that considers the psychosomatic status of the athletes. Our analyses confirmed reductions in both time- and frequency parameters of heart rate variability (p<0.05), indicating deterioration of autonomic regulation in athletes with persistent fatigue. The fact that this was mostly true for the parasympathetic part of the autonomic nervous system (HF, LF/HF, p<0.001) may indicate that the main mechanism of fatigue is insufficient post-load recovery. Although indirectly, this also evidenced resting hemodynamic parameters, in particular, a higher heart rate and arterial blood pressure level in the main group.

Conclusions. Athletes with clinically significant persistent fatigue demonstrated poorer indices reflecting subjective well-being (sense of well-being, anxiety, and sleep quality) and autonomic regulation of cardiac function (arterial blood pressure and heart rate variability parameters). The strongest correlations of fatigue levels were recorded with the WHO-5 Well-Being Index (r=–0.902), insomnia severity (r=0.691), and daytime sleepiness (r=0.684), indicating the systemic nature of these changes. The findings suggest that the disturbances in functional indicators may result from insufficient post-load recovery, which underscores the need for further research on the effectiveness of various recovery interventions aimed at optimizing the physiological state of athletes.