Bioelectrical impedance analysis (BIA) estimates body composition based on electrical resistance (R) by applying a weak alternating current to the body. When currents with multiple frequencies are used, the current path differs depending on the frequency. The current at 0 Hz did not penetrate the cell membrane, whereas the cells became transparent to the current at an infinite Hz. Therefore, a lower density of muscle cells results in a lower R of 0 Hz current (R0) and a smaller difference with R of the ∞ Hz current (R∞), i.e. closer to 1.0. This study investigated the potential of the R of high- and low-frequency currents ratio for assessing muscle quality. First, R0, R∞ and their ratios (R∞/0; R-ratio) were compared in 30 healthy males with limbs extended and in a flexed state. Although R0 and R∞ are greatly reduced by limb flexion, the reduction in R-ratio is small. Therefore, although R0 and R∞ indicate the conductor’s resistance, R-ratio does not. Second, the ratio of R for 250 and 5 kHz currents was compared among students majoring in sport in university, 29 with large and 31 with small body physique, and 34 students who were not majoring in sport. Sport students with small body physique had lower R-ratio, even though there was no difference in body physique between non-sport students. R-ratio was not significantly different among the sport students, even though they differed in their body physique. Therefore, these results suggest that the R-ratio may reflect differences in physical activity status.