Social isolation negatively affects physical fitness by reducing opportunities for engaging in physical activity and social support. Individuals who are socially isolated often experience decreased motivation to exercise, which can lead to sedentary behavior and subsequent weight gain. This lack of physical activity contributes to various health issues, including cardiovascular diseases, diabetes, and mental health disorders. To counteract the effects of isolation, fostering social connections and engaging in group fitness activities can enhance both physical fitness and overall mental well-being.