Effect of pre-competition weight loss on onautonomic regulation and functional state qualified powerlifters

Background and purpose of the study.Pre-competition weight loss is a common practice among powerlifters to compete in lower weight categories. However its impact on autonomic regulation and functional status in female powerlifters remains poorly understood. This study aimed to evaluate the effect of rapid weight loss on HRV in qualified female powerlifters, focusing on changes in sympathetic and parasympathetic activity. The hypothesis was that pre-competition weight loss would lead to a decrease in HRV, an increase in sympathetic activity, and a decrease in parasympathetic regulation, indicating physiological stress. Materials and methods. The study enrolled 31 qualified female powerlifters (candidates for master of sports). HRV was measured before and after a 5-10-day weight loss period using a portable cardiomonitor. Key HRV parameters were analyzed, including SDNN, rMSSD, LF, HF, and the LF/HF ratio. Statistical analysis was performed using a paired t-test in Statistica 11.0, with significance set at p < 0.05. Results. Significant decreases in SDNN (p < 0.001), rMSSD (p < 0.001), and HF (p < 0.01) were found, indicating a decrease in parasympathetic activity. In contrast, LF (p < 0.001) and the LF/HF ratio (p < 0.001) increased, reflecting an increase in sympathetic activity. No significant changes in heart rate (HR) or RR intervals were found (p > 0.05). Conclusions. Pre-competition weight loss in skilled female powerlifters results in significant changes in HRV, characterized by increased sympathetic activity and decreased parasympathetic regulation. These changes indicate physiological stress and potential risks to cardiovascular health. The results highlight the need for individualized weight management strategies to minimize negative impacts on autonomic regulation and overall health.