This cross-sectional study determined physical-fitness levels of more than 1,000 Japanese older men and women, including 338 participants who were 75 years of age and older. Each participant performed 11 tests representing 4 domains of functioning (muscular, joint, neural, and respiratory). Two-way ANOVA was used to examine gender and age differences for each variable. Performance on every test decreased with advancing age, but the declines did not occur at a uniform rate. In addition, men and women did not decline at the same rate for each variable. Although leg strength, balance ability, and reaction time did not decline until after the age of 65, they exhibited the steepest decline of all the variables after age 75. These findings suggest that significant declines in physical fitness occur with advancing age, especially those that are related to mobility and risk for falls.