Don't put all your eggs in one basket when it comes to exercise - doing a variety of different physical activities every week is the key to boosting your health and living longer, a study suggests. After tracking the weekly exercise habits of 110,000 men and women in the US for 30 years, researchers found active people who did the greatest variety of exercise were 19% less likely to die during that time than those who focused on one activity. That effect was greater than for individual sports