If you keep up with health and fitness news, you probably don’t need another reason to be active. Most people already know that exercise can help you lose weight; manage your blood glucose, blood pressure and cholesterol levels; and lower your risk for serious heart problems. But did you know that even a small amount of physical activity makes a big difference? A new study from Kaiser Permanente in Southern California has found that just a little bit of exercise can slash your risk for heart disease, diabetes and other chronic conditions–often by more than half.