Resistance training is considered the most effective intervention for increasing older people's muscle mass and strength. Thus, we created the Sukubara®, a self-administered training system (squat + balance training) that incorporates a new low-load exercise. In this study, we hypothesize that introducing Sukubara will positively affect skeletal muscle mass and physical function. A preliminary verification was carried out on healthy, non-elderly participants who were recruited from the hospital staff. Participants were randomly assigned to two groups for a 12-week intervention: the resistance training group (R group) that performed the Sukubara exercise program and the control group (C group) that did not. This study's primary end¬point was a change in skeletal muscle mass, while the secondary endpoints were knee extension strength and one-leg standing time with eyes closed. An analysis of the 18 participants (R group = 8; C group = 10) was performed. Results showed that skeletal muscle mass, knee extension strength, and one-leg standing time were significantly improved or tended to be significantly higher in the R group than in the C group. Our study concluded that, by incorporating low-load exercise, Sukubara resulted in muscle hypertrophy and improved physical function.