Attenuation of the influence of cardiolocomotor coupling in heart rate variability interpretation during exercise test

During exercise test, cardiolocomotor coupling related components appear in heart rate variability (HRV), blurring its interpretation as autonomic nervous system (ANS) marker. These cardiolocomotor coupling related components are centered at the pedalling and running stride frequency, as well as at their aliases, and may overlap with the low frequency (LF) and high frequency (HF) components of HRV. In this work cardiolocomotor-related HRV components are studied during maximal exercise test on treadmill and cycle ergometer. Power in the bands related to cardiolocomotor coupling increases with exercise intensity in cycle ergometer but not in treadmill exercise test, where it displays higher values for all exercise intensities. A method is proposed to reduce the effect of this coupling in the interpretation of HRV. Evolution of the power in the low frequency (LF) and high frequency (HF) bands are studied after the proposed reduction of cardiolocomotor coupling, showing more significant changes with exercise intensity than before the method is applied.