Exercise physiology is the study of how the body responds and adapts to exercise. It examines the effects of exercise on body systems from acute to chronic adaptations. Physical activity provides numerous health benefits by enhancing cardiorespiratory endurance, muscular strength and endurance, flexibility, and body composition. Programs should be designed using the FITT principle and individual goals, abilities, and needs to optimize health and fitness benefits while avoiding injury or disorders like anorexia or bulimia.