ABSTRACT
The early classic epidemiological studies associating physical activity and cardiovasclar disease were conducted in the 1950s and 1960s in England and the USA on London bus conductors and San Francisco longshoremen. Strokes are cerebrovascular events usually associated with ischemia in blood vessels supplying the brain. This ischemia leads to nerve death and thus damage to speech, sight and behavior and often paralysis. Osteoporosis is characterized by a decreased bone mass and structural deterioration of bone tissue leading to bone fragility. The disease increases the risk of fractures, especially on falling, and is associated with the aging process. Osteoarthritis is the most common arthritis and is characterized by degeneration of cartilage and growth of new bone around the joint. Incidence of the disease increases with age and is a common cause of inactivity in elderly persons.
