Many older adults do not adhere to the recommended physical activity levels. This study examines the gait changes upon longdistance walking among healthy older adults. Gait tests of 24 adults aged 65 or more were conducted at baseline and at the end of 30 and 60min of treadmill walking. Spatial temporal, kinematic, and kinetic gait data were computed. Perceived level of exertion was evaluated for each subject. Ten subjects (group B) perceived higher exertion levels than the remaining 14 subjects (group A). After walking, group B had significant reductions in dominant-side ankle joint range of motion and power, suggesting lower-leg muscle fatigue, which appeared to be compensated by significantly increased nondominant-side knee and hip motions. These changes were not observed in group A. Differences in gait parameters between groups A and B implied that some biomechanical factors might contribute to the lack of walking of some older adults.