Dynamics of heart rate changes following moderate and high volume exercise training

In this study, we use the complex correlation method derived from the Poincaré map along with standard SD1 and SD2 parameters to obtain a better understanding of the relationship between optimal autonomic control of the heart rate and the correlation to fitness and exercise. Fifty participants were randomized into a moderatevolume (n=19), high-volume (n=15) and control group (n=16). The duration of the signal is divided into Day (9am-6pm), Night (12am-6am) and 24h groups. Standard Poincaré based parameters of heart rate variability SD1, SD2, SD1/SD2 and complex correlation measure (CCM) was calculated for each subject and duration. CCM indicated that there was a greater change associated with moderate volume exercise (median ± iqr 19.96 ± 29.62 vs 14.76 ± 23.14) compared to high volume exercise during the Day with both being significantly different to control (p<0.05). We conclude that autonomic balance and heart rate variability affects day time function more so than night time function, as metabolic and physiological processes slow down during the night.