Trajectories of physical function during a 12-week resident-led health promotion program (HATSURATSU) among community-dwelling older adults in Japan

AIM: To describe short-term trajectories of physical function during participation in a 12-week resident-led health promotion program among community-dwelling older adults in Japan. METHODS: 78.6 ± 6.3; 69.1% women) in Niyodogawa Town, Kochi Prefecture, Japan. The program was conducted twice a week and included stretching, lower-limb exercise training, health education, and community activities. RESULTS: Significant improvements were observed in functional measures, including the Timed Up and Go (TUG) test, balance, maximum gait speed, and the 30-second chair stand (CS-30) test. Notably, CS-30 improved significantly from the 2nd week, TUG and gait speed improved from the 3rd week, and balance improved from the 9th week. No significant changes were found in body mass index, appendicular skeletal muscle mass index, or grip strength. The average participation rate of 82.3% reflects the program's strong appeal among older adults and highlights its potential for self-sustainability through participant-led efforts. CONCLUSIONS: During participation in the 12-week HATSURATSU program, favorable short-term changes were observed in several physical function measures. However, because this study used a single-arm repeated-measures design, these findings should not be interpreted as definitive evidence of causal intervention effects. Post-intervention continuity, long-term sustainability, and broader social impact should be examined in future studies with controlled designs and longer follow-up.