Heart Rate Variability Alterations During Delayed-Onset Muscle Soreness-Inducing Exercise-With Piezo2 Interpretation

Area of Science:

• Sports Medicine
• Exercise Physiology
• Autonomic Neuroscience

Background:

• Heart rate variability (HRV) is influenced by pain and physiological stress.
• Delayed-onset muscle soreness (DOMS) is a common consequence of strenuous exercise, often associated with oxidative stress and microdamage.
• Understanding HRV alterations during exercise-induced DOMS can provide insights into the underlying physiological responses and injury mechanisms.

Purpose of the Study:

• To investigate whether heart rate variability (HRV) changes during exercise are affected by the subsequent development of delayed-onset muscle soreness (DOMS).
• To analyze the relationship between heart rate (HR) and HRV parameters during a DOMS-inducing exercise protocol in elite athletes.
• To explore the potential of HRV as a biomarker for detecting early signs of neural microdamage associated with DOMS.

Main Methods:

• Nineteen young male elite handball players underwent an isokinetic dynamometer exercise session designed to induce DOMS.
• Heart rate variability (HRV) measurements were continuously recorded throughout the exercise session.
• Time-frequency domain HRV parameters and sample entropy were analyzed in relation to heart rate (HR) and DOMS severity.

Main Results:

• The relationship between HR and time-frequency HRV parameters followed an exponential-like function, while entropy exhibited a V-shaped pattern.
• DOMS induction led to an overall increase in time-frequency HRV parameters and a decrease in sample entropy, suggesting sympathetic nervous system upregulation.
• HR-dependent sample entropy showed significant nonlinear differences between low-DOMS and high-DOMS groups, with lower values at lower HRs and higher values at higher HRs in the high-DOMS group.

Conclusions:

• Nonlinear alterations in HRV occur in a heart rate-dependent manner during exercise that induces DOMS.
• Systematically downshifted sample entropy values indicate an upregulated sympathetic tone preceding or accompanying DOMS.
• These findings provide indirect evidence of initiating neural microdamage in DOMS and suggest HRV analysis could aid in monitoring injury risk in sports.