Stress can adversely affect physical health and fitness by triggering the release of cortisol and other hormones, which can lead to weight gain, hypertension, and decreased immune function. Additionally, stress can diminish motivation to exercise and promote unhealthy coping mechanisms, such as overeating or sedentary behaviors. Managing stress through healthy outlets, such as physical activity or mindfulness, can mitigate these effects, fostering resilience and promoting a more balanced lifestyle.