Physical activity is described as any physical movement made by the skeletal muscles, which necessarily requires muscular energy expenditure. Physical activity covers all activities, at any level, carried out during any given time of the day or night. It includes movement and incidental activity incorporated into daily activity. Some activities may be categorized as aerobic activity and some as anaerobic activity.
Aerobic physical activity is carried out in a continuous and rhythmic flow; it involves short bursts of maximal effort with a sufficient recovery period. It can be performed by using short stretches of the muscles. Cycling, jogging, walking, dancing and swimming are examples of aerobic exercises. Anaerobic activity on the other hand, is any physical activity that uses large muscles in a short period of time; it may involve heavy lifting, throwing a ball, lifting a heavy object, playing football, wrestling or cycling. A good example of an anaerobic activity would be a sprinting marathon.
Anaerobic exercise is generally associated with weight training because the muscles required in this type of physical activity require a lot of power and strength. Examples of anaerobic activities would be swimming, weightlifting, cycling and rowing. Bone-strengthening activity has become very popular in recent times. This type of physical activity strengthens bones by increasing the number of lean body units (muscles). Activities such as walking, cycling and stair climbing are examples of bone-strengthening exercise.