"Physical activity is defined by the World Health Organization as any bodily movement produced by skeletal muscles that requires energy expenditure, while exercise is a form of physical activity that is planned, structured, repetitive, and performed with the goal of improving health or fitness. So, although all exercise is physical activity, not all physical activity is exercise. The health-related components of physical fitness are cardiorespiratory endurance, flexibility, muscular strength, muscular endurance, and body composition."