Cardiorespiratory Coupling is Associated with Exercise Capacity in Athletes

Abstract

The aim of this study was to evaluate the cardiorespiratory coupling (CRC) of athletes at rest and to verify its relationship with exercise capacity. We studied 50 men (25 athletes and 25 non-athletes) at rest in supine condition. The CRC was determined via squared coherence function K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> between heart period (HP) and respiratory (RESP) variabilities in high frequency (HF) band [K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (HF)], while the exercise capacity was assessed via the peak oxygen uptake (VO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> peak) measured during cardiopulmonary exercise testing. The results showed that K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (HF) index was significantly correlated with VO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> peak (r=0.4, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$p=0.03$</tex> ). This result suggests that CRC is associated with physical exercise capacity in athletes. This finding might open new possibilities on how to improve VO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> peak above and beyond the application of demanding sessions of heavy physical exercise.