Physical activity is recognized as a fundamental factor in maintaining health, preventing diseases, and improving quality of life. With the increasing prevalence of sedentary lifestyles, the significance of physical activity has become more pronounced, leading to a surge in scientific research in this field. The book Physical Activity Research provides a comprehensive perspective on the physiological, psychological, and performance-related effects of physical activity. It delves into topics such as the role of physical activity in metabolic health, the prevention and management of chronic diseases, physical activity requirements across different age groups, and training strategies to enhance athletic performance. This book serves as a valuable resource for academics, coaches, sports scientists, and health professionals. We hope that this work, prepared to deepen the scientific understanding of physical activity and promote healthier lifestyles, will contribute to ongoing research and practical applications in the field.