Abstract: Purpose: There are few reports of long-term follow-up of changes in health status, including convalescent rehabilitation, in frail elderly adults.This study aimed to compare changes in physical strength between community-dwelling elderly adults with and without prefrailty after 4 years of participation in a preventive healthcare class.Methods: Prefrailty was defined as grip strength <30 kg for the men and <20 kg for the women.Health exercise classes had been con ducted since 2011.Subjects were divided into two groups (with prefrailty and without prefrailty) based on grip strength before partici pation.We compared the changes in grip strength and 10-m walking speed after 4 years between the two groups.Results: From 2011 to 2015, 178 people (50 men and 128 women) participated in the class es, including 19 men and 35 women with prefrailty.Twenty-two men and 43 women participated in the classes for 4 years, including 3 men and 6 women with prefrailty.Change in grip strength after 4 years was -0.49±1.11kg for those with prefrailty and -1.34±0.50kg for those without.Change in walking speed was +0.10±0.17m/s for those with prefrailty and +0.04±0.08 m/s for those without.There were no significant gender differences.An analysis of covariance using age as a co-variable showed that the change of grip strength was significantly different between two groups (with prefrailty and without prefrailty)(p<0.05).Conclusions: Continued participation in preventative healthcare classes effectively increases leg strength, even in elderly adults with prefrailty.