Respostas neuromusculares, termorregulatórias e oxidativas ao treinamento de força tradicional e excêntrico em atletas de powerlifting paralímpico

Abstract

Introduction: Powerlifting is a maximal strength sport characterized by the execution of three multi-joint movements: the squat, bench press, and deadlift, requiring high levels of neuromuscular control and mechanical efficiency. In the Paralympic context, due to the functional characteristics of eligible athletes, only the bench press is performed in competition, with specific adaptations implemented to ensure safety, technical standardization, and competitive equity. Objectives: To investigate the acute and subacute effects of traditional and eccentric strength training on neuromuscular, mechanical, thermoregulatory, and oxidative indicators in Paralympic powerlifting athletes, as well as to compare these responses with those of conventional athletes. Methods: This thesis consisted of three experimental studies involving trained male Paralympic powerlifting athletes. Neuromuscular indicators were assessed, including maximum isometric force (MIF), rate of force development (RFD), time to maximum isometric force (TMIF), and muscle activation measured by surface electromyography (sEMG) of the pectoralis major (sternocostal and clavicular portions), anterior deltoid, and triceps brachii (long head). Mechanical variables included peak velocity (Vmax), mean propulsive velocity (MPV), and power output (POT), while thermoregulatory responses were evaluated באמצעות skin temperature (Tsk). Oxidative stress was assessed using biomarkers such as thiobarbituric acid reactive substances (TBARS) and sulfhydryl groups (SH). Measurements were performed at baseline, immediately post-exercise, and at 24 and 48 hours following traditional and eccentric training sessions, using protocols based on relative loads (%1RM). Results: The findings demonstrated that eccentric training elicited more pronounced physiological responses, characterized by increased skin temperature, greater elevations in oxidative stress markers, and enhanced neuromuscular adaptations at specific time points, although it was also associated with greater fatigue and prolonged recovery. In contrast, traditional training produced more stable responses, with faster recovery of performance indicators. Conclusion: Eccentric training appears to be an effective strategy for promoting relevant neuromuscular and physiological adaptations in Paralympic powerlifting athletes, although it requires careful management of fatigue and recovery. Conversely, traditional training represents a more stable approach, particularly suitable for maintenance phases and competitive preparation. A strategic combination of both methods may optimize athletic performance while respecting the physiological and functional specificities of Paralympic athletes, reinforcing the need for individualized training prescription.