Análise do treinamento sobre os indicadores neuromusculares, temperatura da pele, ativação muscular e assimetrias no powerlifting paralímpico e convencional

Abstract

Introduction: Powerlifting competitions require consistent and symmetrical lifting, as any asymmetry results in a failed attempt. Indicators such as velocity, power, and skin temperature are crucial for monitoring training loads in both conventional (CP) and Paralympic (PP) athletes. Strength training is essential for athletic performance and rehabilitation, benefiting both conventional and Paralympic powerlifters. Objectives: To compare and analyze movement asymmetry, peak velocity (Vmax), mean propulsive velocity (MPV), power output (POT), skin temperature (ST), static strength indicators (maximum isometric force – MIF, rate of force development –RFD, time to maximum isometric force – TMIF), and muscle activation (sEMG) of the sternocostal portion of the pectoralis major and the long head of the triceps brachii between CP and PP athletes, before and after a training session. Methods: Twenty- four trained male athletes (12 CP and 12 PP) participated in the study. MPV, Vmax, and power were assessed at 45% of 1RM before and after a 5x5 training session at 80% of 1RM. For the 80% 1RM load, MPV, Vmax, and power were measured during the first and last sets of the 5x5 protocol. Velocity, power, ST, MIF, RFD, and sEMG (pectoralis major – sternocostal portion and triceps brachii – long head) were assessed at 45% 1RM before and after the training session. Results: PP athletes demonstrated lower velocity and greater symmetry at 45% 1RM, but higher velocity and less asymmetry at 80% 1RM compared to CP athletes. The data suggest that PP athletes tend to be slower at lower intensities and faster at higher intensities in absolute terms, while showing greater symmetry than CP athletes. Only the CP group showed significant differences in Vmax (p < 0.015), MPV (p < 0.007), and power (p < 0.022) between time points. The CP group also exhibited significant increases in MIF (Δ +146.1 N, p < 0.001) and RFD (Δ +36,851.3 N/s, p < 0.001), while the PP group showed no significant changes. The CP group demonstrated a significant reduction in sEMG activity of the pectoralis major (p = 0.026), with no changes observed in the PP group. Conclusion: Despite potential instability caused by lower limb impairments in the PP group, they exhibited lower levels of asymmetry compared to CP athletes. Adaptations to sport-specific rules and training seem to promote technical refinements that reduce asymmetry. Assessments at 45% 1RM revealed distinct effects on velocity, power, and ST metrics between CP and PP athletes after a traditional training session. CP athletes showed significant acute neuromuscular adaptations, while PP athletes maintained stable levels, possibly due to long-term adaptations and motor pattern specialization. These findings highlight the need for individualized training approaches for Paralympic athletes.