While past research has largely supported the importance of physical activity for the health of older adults, during the COVID-19 pandemic, older individuals may have reduced their opportunities and levels of physical activity to lower the risk of infection by minimizing outings or interactions with others. Additionally, the adequacy of medical resources in a region is often closely related to factors such as infrastructure and economic resources. Therefore, it is important to consider whether there are differences in health promotion among older adults living in areas with varying levels of medical resources. This study aimed to implement a physical activity program for older adults, selecting Keelung City, Taiwan, as the implementation area, and comparing the differences in implementation effectiveness among administrative districts with different levels of medical resources in the city. The study employed a two-way analysis of variance to examine the differences in the effectiveness of the physical activity program among administrative districts, where the average service population in medical institutions was higher or lower than the city average. The results revealed significant improvements in participants’ right-hand grip strength and the number of sit-to-stand repetitions in the overall sample after the program intervention. Moreover, in administrative districts where the average service population in medical institutions was higher than the city average, participants showed greater improvement in grip strength, while in districts where it was lower than the city average, participants demonstrated greater improvement in sit-to-stand repetitions. Future research could draw upon these findings to design physical activity programs tailored to different regions with distinct allocations of medical resources. Tailored program designs considering local medical resources are necessary to optimize effectiveness. Governments and organizations should focus on elderly health, especially in resource-scarce areas, by increasing investment and support for these programs to promote well-being and bridge disparities.