Bioimpedance analysis for identifying new indicators of exercise-induced muscle damage

Abstract

Abstract To date, noninvasive and immediate assessment of muscle tissue status after exercise-induced muscle damage (EIMD) has not been established. This study was designed to assess and determine parameters suitable for measuring EIMD after eccentric exercise, using multi-frequency bioimpedance analysis (BIA). Thirty-five young male participants performed dumbbell exercises with their left arm, and BIA parameters were measured at time points up to 168 h post exercise using a multi-frequency BIA device. At all time points, intra and extracellular water content was greater in the left arm than in the right arm, and the impedance, reactance, resistance, and phase angle were lower in the left arm than in the right arm. Established indices of EIMD, such as maximal isometric voluntary contraction, were measured and used in correlational analyses. Only reactance was highly correlated with biomarkers indicating muscle damage; therefore among BIA parameters, reactance is the most suitable to assess EIMD.