Cardiorespiratory coupling is associated with exercise capacity in athletes: A cross-sectional study

Area of Science:

• Cardiology
• Exercise Physiology
• Biomedical Engineering

Background:

• Cardiorespiratory coupling (CRC) reflects the interaction between heart rate and respiration.
• Understanding the relationship between resting CRC and exercise capacity is crucial for assessing athletic performance.
• Traditional heart rate variability (HRV) analysis may not fully capture the nuances of cardiorespiratory interaction in athletes.

Purpose of the Study:

• To investigate the association between resting cardiorespiratory coupling (CRC) and exercise capacity, measured by peak oxygen uptake (VO2peak).
• To compare this association in athletes versus non-athletes.
• To evaluate the efficacy of traditional HRV analysis versus CRC in predicting exercise capacity.

Main Methods:

• A cross-sectional study involving 42 healthy males (21 athletes, 21 non-athletes) aged 20-40.
• Simultaneous recording of electrocardiogram and respiratory movement for 15 minutes to derive beat-to-beat heart period and respiration series.
• Calculation of CRC using squared coherence function and causal analysis; assessment of exercise capacity via incremental cardiopulmonary exercise testing for VO2peak.

Main Results:

• Resting CRC was significantly associated with exercise capacity in athletes (r=0.4, p=0.03) but not in non-athletes (r=-0.2, p=0.3).
• Traditional high-frequency HRV analysis showed no correlation with exercise capacity in either group (athletes: r=-0.1, p=0.5; non-athletes: r=-0.1, p=0.3).

Conclusions:

• Improved resting cardiorespiratory coupling (CRC) is associated with higher exercise capacity in endurance athletes.
• Resting CRC offers a potential biomarker for assessing athletic performance, particularly in endurance sports.
• Traditional frequency-domain HRV analysis is less sensitive than CRC in detecting the relationship between cardiorespiratory interaction and exercise capacity in trained individuals.