Age- and Sex-Specific Profiles of Self-Reported Functional Limitations, Exercise Behavior, and Objective Functional Fitness in Korean Older Adults: Evidence from Two Independent 2023 Data Sources

Background/Objectives: Self-reported function, exercise behavior, and performance-based fitness describe related but distinct aspects of health in later life. This study compared their age- and sex-specific descriptive profiles using independent Korean datasets. Methods: The 2023 National Survey of Older Koreans contributed 9951 self-respondents; the 2023 National Fitness Award (NFA) dataset contributed 27,440 assessment records, which may not represent 27,440 unique individuals. Age-by-sex profiles were analyzed separately; no individual-level linkage or direct between-dataset statistical comparison was performed. Results: Stair-climbing and 300 m walking limitations, and related objective performance indicators, generally showed less favorable values in older age groups. Exercise non-participation followed a less consistent pattern. Among men, the weighted prevalence was 47.16% (95% CI 43.29–51.04%) at ages 65–69 and 40.88% (36.64–45.13%) at ages 75–79; their exploratory age-group contrast did not remain significant after Holm adjustment (adjusted p = 0.066). Among women, non-participation was 42.47–45.67% across ages 65–79. Conclusions: The observed directional similarities are descriptive and cannot establish agreement, predictive validity, or the effects of exercise at the individual level. Exercise participation reports, task-specific difficulty questions, and objective fitness tests should be regarded as distinct information sources requiring evaluation within the same individuals.