The aim of this study was to compare the effects of class-style supervised intervention (CS) versus home-based unsupervised intervention (HB) in improving muscle mass and physical function in older adults. A total of 288 older adults (65-87 years) living independently participated in this cluster-randomized trial. They were assigned to one of two groups (CS and HB) and instructed on resistance exercise program in two lectures. Also, all participants were provided with exercise materials (ankle weight, Thera-Band, triaxial-accelerometer/pedometer and exercise log), and then encouraged to perform resistance exercise and to increase the mean daily activity level. In CS intervention, the participants conducted a resistance exercise program at weekly class-style sessions. In other days, they performed the program independently. In HB intervention, the participants were only given instruction and practice about exercise. They were also instructed to increase 2,000 steps per day. Lower limb muscle mass (both front thigh muscle thickness and intracellular volume of lower limb) and knee extension strength were significantly increased in both groups. Significant increase in intracellular volume of upper limb was observed only in the CS intervention group. There were significant improvements of physical function (maximal gait velocity and chair-stand time) in both groups. Additionally, the mean number of daily steps significantly increased in both groups. None of these variables showed a significant difference between groups. These results indicated that low intensity resistance training with increase in daily walking steps can induce muscle hypertrophy, strength gain, and improvement of physical function. Particularly, it is important that there was no significant difference in the training effects on lower limb muscle and physical function between CS and HB interventions. Thus, HB intervention is considered a cost-effective method to prevent sarcopenia for elderly with a wide range of physical fitness level. Wide acceptance of this program on a community basis is anticipated for the future.

DESCENTE SPORTS SCIENCE Vol.35/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE