PURPOSE This systematic review and meta-analysis aimed to assess the effectiveness of exercise programs in improving physical fitness among middle-aged adults in Korea. METHODS A literature search was conducted using KCI-registered databases on DBpia, RISS, and KISS up to September 21, 2023. The review followed the PICOSD framework (population: middle-aged adults; intervention: exercise program; comparison: did not participate in exercise program; outcome: physical fitness; study design: randomized controlled trials). Two researchers independently evaluated bias using the Cochrane Risk of Bias tool for randomized trials (RoB 2). The data was synthesized using the CMA 3.0 program, applying a random effects model to estimate the overall effect size using Hedges’g. RESULTS Out of 914 screened documents, 15 studies were selected, comprising 405 participants. The overall effect size for improving physical fitness was significant (g=0.994, 95% CI: 0.712–1.276). Sub-analysis indicated significant improvements in various components, including muscle strength (g=1.295, 95% CI: 0.909-1.682), muscular endurance (g=0.972, 95% CI: 0.637-1.308), cardiorespiratory endurance (g=1.092, 95% CI: 0.453–1.731), flexibility (g=0.883, 95% CI: 0.555–1.210), muscle power (g=1.421, 95% CI: 0.656– 2.186), and agility (g=1.854, 95% CI: 0.347–3.361) compared to the control group. An additional analysis focusing solely on women revealed a slight increase in effect size, although the order of effect sizes remained consistent across fitness components. CONCLUSIONS This meta-analysis confirms the effectiveness of exercise programs in enhancing physical fitness in middle-aged adults. The systematic review also highlights key considerations for designing exercise programs for this demographic. Future studies should aim to minimize bias and enhance the quality of reporting to ensure more robust results.
