Dr. Russell Greenfield: Regular exercise is vital for your heart, because it strengthens your heart muscle, but then also does other things to keep your heart functioning well. For example, regular physical activity improves cholesterol levels by increasing good cholesterol or HDL and reducing LDL the bad cholesterol. It improves lung function, burns calories, helps reduce emotional stress, and is an affect of therapy from mild forms of depression. Each of these responses to exercise is good for your heart.
A good fitness regimen should include both aerobic exercise and weight training. Do something aerobic most days of the week. Some activity that makes you break a sweat like a brisk walk, gardening, or swimming. Work up to doing the activity for 30-40 minutes, even if you have split it up into two or three sessions. Strength training works muscles against resistance and should be done at least twice a week. It helps protect against osteoporosis and contributes to optimal weight management by adding metabolically active muscle tissue.
Keep in mind that even low intensity exercise like tai-chi can improve aerobic capacity, lessen stress, and benefit your heart. If you're new to fitness training see your doctor first and consider meeting with a personal trainer to help develop a safe and effective program designed specially for you. Making time for fitness can be hard, but odds are you'll find a way to work it into your busy schedule, because will make you feel so good.