Fitness can significantly impact sleep quality by promoting deeper and more restorative sleep. Regular physical activity helps regulate the body's circadian rhythm and can alleviate issues such as insomnia and sleep apnea. Furthermore, engaging in aerobic or resistance exercises increases serotonin levels, which are crucial for mood stabilization and sleep regulation. However, exercising too close to bedtime can lead to increased alertness, negatively affecting sleep. Overall, a well-balanced fitness routine contributes to better sleep patterns and enhances overall health.