3. Is exercise good for you?

• Physical activity can significantly reduce the risk of cardiovascular disease, diabetes, some forms of cancer, osteoporosis, obesity, falls and fractures, and some mental health problems. • While the benefits of physical activity are clear, there is a slightly increased risk of sudden death while exercising (compared with while sedentary), especially in untrained people undertaking unaccustomed vigorous activity. • Routine exercise testing yields a significant number of false-positive results, and has not been shown to prevent exercise-related acute cardiac events. • There is no convincing evidence that exercise is itself associated with osteoarthritis, but significant joint injury which occurs during sport is associated with an increased risk of subsequent development of osteoarthritis.