Exercise
Moderate exercise is one of the best things you can do to keep your heart and the rest of your body, healthy. Consult with your health provider before beginning a new exercise program. Exercise moderately and within your capabilities, but do it regularly. Exercise helps reduce stress and prevent obesity which in turn is associated with the development of heart disease, diabetes etc. It also helps people with diabetes control their blood sugar.
People who work out seriously and continuously for most of a decade has been seen to cut their age related decline of maximal heart rate in half. Between ages 40-50 check out your VO2 max, the maximum rate at which the muscles use oxygen during peak exercise. The old standard for calculating your target heart rate is (220- your age) x .85. For good cardio fitness, it is advisable to exercise aerobically 90 minutes per week minimum.