Sedentary lifestyle is defined as individuals engaging in behaviors that require low energy expenditure in their daily lives for extended periods. Technological advancements, the widespread use of transportation, sedentary work, and increased screen time are contributing to the increasing prevalence of sedentary lifestyles in society. Insufficient physical activity levels are considered one of the significant risk factors negatively affecting individuals' health. Therefore, reducing sedentary lifestyles and increasing physical activity have become an important public health issue today. Physical activity is defined as any bodily movement that involves the use of muscles and joints and results in energy expenditure. Regular participation in physical activity is known to contribute to the physical, mental, and social development of individuals. Furthermore, physical activity helps reduce the risk of cardiovascular diseases and some chronic illnesses. It also offers significant benefits in terms of reducing stress levels and improving quality of life. This section discusses the concept of sedentary lifestyle and the importance of physical activity. The negative effects of sedentary lifestyles on individuals are evaluated, and the positive contributions of physical activity to health and quality of life are explained. In conclusion, developing a habit of regular physical activity and reducing sedentary behavior is considered an important requirement for protecting individual and public health.