European Journal of Cardiovascular Medicine

This study examines the influence on heart rate variability (HRV) indices in trained individuals as compared to untrained individuals presented in a prospective and cross-sectional study. The predictability of HRV in athletic performance is also included. Finally, some recommendations concerning the application of HRV methods in athletes are made. The cardiovascular system is mostly controlled by autonomic regulation through the activity of sympathetic and parasympathetic pathways of the autonomic nervous system. Analysis of HRV permits insight in this control mechanism. It can easily be determined from ECG recordings, resulting in time series (RR-intervals) that are usually analysed in time and frequency domains. As a first approach, it can be assumed that power in different frequency bands corresponds to activity of sympathetic (0.04-0.15 Hz) and parasympathetic (0.15-0.4 Hz) nerves. However, other mechanisms (and feedback loops) are also at work, especially in the low frequency band. During dynamic exercise, it is generally assumed that heart rate increases due to both a parasympathetic withdrawal and an augmented sympathetic activity. Most studies concern relatively small numbers of study participants, diminishing the power of statistics. In order to further develop this fascinating research field, we advocate randomised, controlled, long-term studies using validated measurement methods. There is a strong need for basic research on the nature of the control and regulating mechanism exerted by the autonomic nervous system on cardiovascular function in athletes, preferably with a multidisciplinary approach between cardiologists, exercise physiologists, pulmonary physiologists, coaches and biomedical engineers. In this study,  we determine the effect of long term endurance training (minimum period of one year) on heart rate variability in trained individuals  as  compared to the sedentary population, so that long term endurance exercise could be used for cardiac wellbeing.