Reliability of a functional electromechanical dynamometer for a bilateral standing press exercise at intensities of 30% and 60% of isometric peak force in trained women

Background Determining the reliability of exercise instruments and protocols in the fields of health and sports performance is of great interest due to their close relationship with monitoring and decision-making in athletes. Studies in trained women are limited, and more evidence is needed on performance variables and the reliability of exercise protocols. Objective This study aimed to evaluate the reliability of an exercise protocol for determining mean muscle strength, mean velocity, and mean power during the bilateral standing press (BSP) in trained women. Methods Sixteen trained women (age = 20.0 ± 2.30 years; body mass = 67.63 ± 6.68 kg; height = 1.65 ± 0.06 m) participated in this repeated-measures study. Absolute reliability was assessed using the coefficient of variation (CV), and relative reliability was assessed using the intraclass correlation coefficient (ICC) for a bilateral standing press (BSP) exercise protocol performed at intensities of 30% and 60% of isometric peak force (IPF). Results Mean muscle strength showed acceptable absolute reliability and extremely high relative reliability at both 30% IPF (CV = 6.51%; ICC = 0.94) and 60% IPF (CV = 5.03%; ICC = 0.97). Mean velocity showed extremely high relative reliability at 60% IPF (ICC = 0.92), but its absolute reliability was not acceptable at either 30% IPF (CV = 10.10%; ICC = 0.75) or 60% IPF (CV = 14.16%; ICC = 0.92). Mean power also exceeded the predefined CV threshold at 30% IPF (CV = 11.16%; ICC = 0.85) and at 60% IPF (CV = 14.35%; ICC = 0.89). Conclusions These findings suggest that the BSP protocol using functional electromechanical dynamometry is reliable for assessing mean muscle strength in trained women. However, mean velocity and mean power should be interpreted with caution, as their absolute reliability did not reach the predefined threshold of acceptable reliability.