Not only does Japan has the world’s longest healthy life expectancy, but also the world’s longest average life span. This study investigated the effect of a novel dual-task (DT) exercise called “Synapsology” (SYNAP), developed as a game-like activity to improve older adults’ physical and cognitive functions. Participants (n=24) with a mean age of 70.6 years (65–77 years) were randomly assigned to the SYNAP exercise group (SG, n=15) and the control group (CG, n=9). The SG participated in the DT intervention consisting of 60-minute sessions, twice a week, for 8 weeks. Physical function in timed-up-and-go had significant pre- and post- trial differences (P=0.017) in SG. In addition, cognitive function results in the a 25-hole trail-making peg test (P=0.004) and an oxidative stress marker (P=0.039) had a statistically significant difference within the SG. However, there were no significant differences in the physical and cognitive functions between SG and CG. In the study, older adults who participated in cognitive-motor DT intervention improved significantly with regard to motor ability and cognitive function results. Thus, a game-like DT exercise may help maintain the healthy life of older adults compared to no intervention.