Difference between exercise and physical activity ?

Physical activity is any type of movement of our body that increases our metabolism and causes our muscles to contract. Examples of physical activity range from playing football to carrying heavy boxes. Exercise itself is actually a subcategory of physical activity. Although works involving in labor do belong to physical activities, they usually use a part of our body over and over again leading to over use that part of our body, which may damage our health. Wile for exercise, we are engaging in a structured program of physical activity intended to help us achieve maximum physical fitness.