The Effect of Exercise Intensity on HRV Following a Resistance Training Session in Active Men

Heart rate variability (HRV), a key indicator for assessing the health of the autonomic nervous system and the body’s recovery status post-exercise, is the focus of this study. HRV refers to the fluctuations in the time intervals between consecutive heartbeats, and its increase or decrease can indicate the level of activity of the sympathetic or parasympathetic nervous system. In this research, ۱۰ young men with at least ۶ months of resistance training experience were evaluated to measure the effects of three different resistance training intensities (۴۰%, ۶۰%, and ۸۰% of one-repetition maximum) on their HRV.Before starting the exercise, the subjects sat in a resting position for about ۵ minutes to measure their baseline HRV. During this time, a Polar H۱۰ chest strap, capable of recording HRV and heart rate, was attached to their bodies, and the data was transmitted in real-time to the HRV Elite software. This method allowed researchers to accurately observe the impact of resistance training on HRV.HRV, as an important factor, was also evaluated after each resistance training session. Following each protocol, subjects were assessed at different time intervals to examine changes in HRV over time. The results showed a decrease in HRV immediately after the exercise, indicating an increase in sympathetic nervous system activity and the body’s response to the stress induced by the workout. However, over time and during recovery, HRV began to increase again. Nonetheless, even after a period of recovery, HRV remained lower than its pre-exercise levels. These changes demonstrated the impact of resistance training on the nervous system and the body's need for sufficient time to recover.The data collected from this study were processed using specialized HRV analysis software called Kubios, which allowed detailed analysis of HRV parameters, including both time-domain and frequency-domain indices. The analysis showed that exercise intensity influenced the decrease in HRV after the workout, with lower intensity protocols causing less reduction in HRV, suggesting less stress on the body in these conditions.

کلیدواژه ها:

Resistance Exercise ، Blood Pressure ، Heart Rate Variability ، HRV