THE EFFECT OF AGE AND GENDER ON HEART RATE VARIABILITY FOLLOWING ENDURANCE TRAINING

Abstract

This research investigated the effect of standardized/quantified endurance training on autonomic nervous system control of the heart. The latter was analyzed from spectral analysis of electrocardiogram records of heart rate variability (HRV) during both rest and sub-maximum exercise in groups of older (40–45yrs) and younger (19–21yrs), mixed gender groups (6 males and 6 females), pre and post standardized training. All subjects were recreational runners who completed the same 12 week running program. Previously and subsequent to training, heart rate variability (HRV) was measured during supine rest, 70 degree head-up tilt, and standardized sub-maximum cycling. There was a significant group mean decrease in heart rate both at rest (5%), and during sub-maximum exercise (6%), in both age groups after training. Total spectral power increased (59%), and high frequency power (HFP) (0.15–0.5Hz) increased 166% in both age groups at rest. The younger group showed a greater increase in total power (73%) and young females increased most in total power (112%). There was a significant increase in heart rate response (6%) to 5 minutes of 70 degree head-up tilt in both groups following training. It is concluded that the significant increase in HRV, total power and HFP following training are better indicators of improved cardiovascular condition than a resting heart rate index. HRV measurement provides and effective, non-invasive assessment of cardiovascular adaptation to aerobic training. Supported by The Heart and Stroke Foundation of B.C. & Yukon