BACKGROUND COVID-19 has spread rapidly around the world and reached pandemic proportions. With no definitive treatment to date, prevention is critical, and strengthening the immune system is a valuable tool in reducing the risk of infection. While the aging process can weaken the immune system, physical activity may boost it. OBJECTIVE The review intended to examine the interaction between the changes in the immune system during aging and the development of a COVID-19 infection, focusing on pathophysiological factors, and to evaluate whether regular physical activity can strengthen the immune system in older adults. METHODS The research team performed a narrative review by searching databases. RESULTS During the COVID-19 pandemic, older people can stay active and healthy through playing sports such as yoga, walking, jogging, and cycling. Also, they can use online or virtual yoga and Pilates classes and videos, perform resistance exercises with minimal facilities at home, and do daily housework, such as gardening. CONCLUSIONS In general, due to the positive role of regular exercise training on the immune system of the older adults as well as the involvement of the immune system in COVID-19, it's necessary to guide and implement home-based exercises for older adults.