Stress levels can negatively affect exercise performance by causing physical and mental fatigue. High levels of stress may lead to muscle tension, reduced coordination, and impaired focus, all of which can hinder workouts. Moreover, chronic stress can lead to burnout, decreasing motivation to exercise. The hormonal responses to stress, such as increased cortisol, can also affect muscle recovery and fat metabolism. Finding effective stress management techniques, such as mindfulness and adequate rest, can optimize fitness performance and improve overall health outcomes.