Bioelectrical impedance analysis to estimate one-repetition maximum measurement of muscle strength for leg press in healthy young adults

Abstract

Resistance training (RT) progress is determined by an individual’s muscle strength, measured by one-repetition maximum (1RM). However, this evaluation is time-consuming and has some safety concerns. Bioelectrical impedance analysis (BIA) is a valid and easy-to-use method to assess skeletal muscle mass (SMM). Although BIA measurements are often correlated with muscle strength, few studies of 1RM for RT and BIA measurements are available. This observational study examined the relationship between 1RM and BIA measurements and developed BIA-based prediction models for 1RM. Thirty-five healthy young Japanese adults were included. SMM and the skeletal muscle mass index (SMI) were measured using the BIA device. In addition, dominant-leg 1RM was measured using a unilateral leg-press (LP) machine. The correlations between BIA measurements and 1RM were calculated, and simple regression analyses were performed to predict 1RM from the BIA variables. The results showed significant correlations between 1RM and dominant-leg SMM (R = 0.845, P = 0.0001) and SMI (R = 0.910, P = 0.0001). The prediction models for 1RM for LP derived from SMM of the dominant leg and SMI were Y = 8.21x + 8.77 (P = 0.0001), R2 = 0.73, and Y = 15.53x − 36.33 (P = 0.0001), R2 = 0.83, respectively. Our results indicated that BIA-based SMI might be used to predict 1RM for LP accurately.

On the Run—Comparing Bioimpedance Analysis (BIA) Using Portable Devices

“…BIA measures the resistance (R) when an alternating current of low intensity and high frequency flows between electrodes placed on the body's extremities, which is inversely proportional to the quantity of water and electrolytes [2]. Using a portable BIA device allows for quick measurements of lean and fat body mass [3]. Of note, when performed in different positions (standing or lying down), the fluid and electrolyte distribution in the body will not be the same and may influence the results [4].…”