The Experimental groups or physical activity groups were assigned to three groups based on their muscle mass: normal, probable sarcopenia, and sarcopenia groups. The volunteers were provided with instructions on individual physical activities to be practiced at home for 30 weeks, 2-5 days per week and 50 minutes per session. These physical activities consisted of flexibility exercise for 10 minutes, aerobic exercise for 20 minutes, and resistance exercise for 20 minutes, as outlined in supplement 1. The volunteers were instructed on exercise techniques and physical activities by either sports scientists or registered nurses, and caregivers such as relatives or staff from the social club for older adults were allowed to be present during practice.

The control group did not receive any intervention apart from general suggestions and continued with their usual daily activities.

resistance, aerobic, and flexibility exercises

Sarcopenia status was assessed through three aspects, including a muscle strength test using handgrip strength measured with a dynamometer, a physical performance test using the Short Physical Performance Battery (SPPB), and an appendicular skeletal muscle mass (ASM) test measured with the ACCUNIQ BC 380 tool based on bioelectrical impedance analysis (BIA). The results were aligned with the standards set by the Asian Working Group for Sarcopenia (AWGS). Sarcopenia was diagnosed by low ASM with low muscle strength or low physical performance, dynapenia was diagnosed by low muscle strength only, and pre-sarcopenia was diagnosed by low ASM or low physical performance. Participants underwent assessments both at the beginning and at the 30-week endpoint.

Muscle strength, specifically handgrip strength, was measured using a hand-held dynamometer. Participants gripped the dynamometer with their dominant hand while standing, maintaining their upper arm close to the body and their elbow bent to 90 degrees, exerting maximum force. This test was conducted twice, and the superior result was recorded. Low muscle strength was diagnosed if the handgrip strength was < 26 kilograms in males and < 18 kilograms in females. Participants underwent assessments at both the beginning and the 30-week endpoint.

The physical performance test utilized the Short Physical Performance Battery (SPPB) to evaluate physical function, with a maximum score of 12 points. Low physical performance was diagnosed if the SPPB score was ≤ 9. Participants underwent assessments at both the beginning and the 30-week endpoint.

Appendicular skeletal muscle mass (ASM) was measured using the ACCUNIQ BC 380 tool based on bioelectrical impedance analysis (BIA), and the Skeletal Muscle Mass Index (SMI) was calculated by dividing ASM in kilograms by the height in meters squared. Low muscle mass is diagnosed if SMI is < 7.0 kilograms/meter^2 in men and < 5.47 kg/m^2 in women. Participants underwent assessments at both the beginning and the 30-week endpoint.

Frailty phenotype assessment followed Fried et al.'s (2001) criteria, including weakness, slowness, unintentional weight loss, exhaustion, and low physical activity. Participants were categorized as "frail" if they met three or more criteria, "pre-frail" with one or two, and "robust" if none were fulfilled.

(i) Weakness: Handgrip strength measured with a dynamometer. (ii) Slowness: Assessed by the time taken in a 15-feet walk test. (iii) Unintentional Weight Loss: Evaluated by recording weight loss exceeding 10 pounds or 5% in the last 3 months.

(iv) Exhaustion: Assessed with two questions from the CES-D depression scale. (v) Low Physical Activity: Determined by asking about the frequency of moderate physical activities in the past week.

Participants underwent assessments at both the beginning and the 30-week endpoint.