Patients with type 2 diabetes often suffer from reduction in muscle mass and strength. Recent studies reported that high-intensity resistance training improves physical function, however, it was difficult for all patients to perform that. Radio calisthenics, which has been considered as a therapeutic exercise to promote health in Japan, is a simple exercise that can be done regardless of age and can move the muscles and joints effectively according to the rhythm of radio. Here we investigated the impact of Radio calisthenics for muscle mass in patients with type 2 diabetes. A total of 42 patients whom hospitalized in the Kyoto Prefectural University of Medicine were recruited. Skeletal muscle index (SMI) was defined as appendicular muscle mass(kg) divided by the square of the height (m). Change of SMI means the difference of SMI between the end and beginning of the hospitalization. Among 42 patients, 15 patients (11 males and 4 females) performed the Radio calisthenics. The change of SMI in Radio calisthenics exercisers was significantly lower than that in non-exercisers (-0.008±0.085 vs. -0.273±0.063, p=0.016). Radio calisthenics was positively associated with the change of SMI (standardized partial coefficient, beta = 0.395, p= 0.039) (Table). Radio calisthenics prevents the reduction of skeletal muscle mass and it could be one of the effective exercises for patients with type 2 diabetes. Disclosure T. Kimura: None. T. Okamura: None. Y. Hashimoto: Research Support; Self; Asahi Kasei Pharma. T. Senmaru: None. E. Ushigome: Speaker's Bureau; Self; Astellas Pharma Inc., AstraZeneca, Daiichi Sankyo Company, Limited, Johnson & Johnson, Kyowa Hakko Kirin Co., Ltd., Mitsubishi Tanabe Pharma Corporation, Novo Nordisk Inc., Sumitomo Dainippon Pharma Co., Ltd., Takeda Pharmaceutical Company Limited. M. Hamaguchi: None. M. Asano: None. M. Yamazaki: None. M. Fukui: Research Support; Self; Astellas Pharma Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo Company, Limited, Eli Lilly and Company, Johnson & Johnson, Kyowa Hakko Kirin Co., Ltd., Merck & Co., Inc., Mitsubishi Tanabe Pharma Corporation, Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Sanofi, Sanwa Kagaku Kenkyusho, Takeda Pharmaceutical Company Limited. Speaker's Bureau; Self; AstraZeneca, Eli Lilly and Company, Kowa Pharmaceutical Europe Co. Ltd., Kyowa Hakko Kirin Co., Ltd., Merck & Co., Inc., Mitsubishi Tanabe Pharma Corporation, Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Sanofi, Sanwa Kagaku Kenkyusho, Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited.