February may be known for boxes of chocolates and sugary greeting cards, but it's also the month to celebrate that most important of muscles: the heart. Cardiovascular diseases claim nearly 700,000 lives in the U.S. each year, making them the nation's leading killer. So this American Heart Month, show a little love to your ticker by getting it in tiptop shape. Check out these six simple healthy-heart tips that will help lower your risk for heart disease.

1. Hit the gym
The cornerstone to having a healthy heart is maintaining a healthy weight, according to the Food and Drug Administration, and exercise is an integral part of keeping your heart healthy. Not only does regular physical activity keep you fit, it improves heart function, lowers blood pressure and blood cholesterol, and boosts energy. The National Heart, Lung and Blood Institute recommends at least 30 minutes of moderate physical activity most days of the week, and the more vigorous the activity, such as aerobics or running on a treadmill, the better.

2. Eat your greens (and browns)
A low-fat, low-cholesterol diet rich in fruits, veggies, whole grains and fiber is ideal for a healthy heart. Researchers in Connecticut have reported that broccoli improves heart function and protects against heart disease and damage in lab rats. Substitute baked, steamed, boiled or broiled foods for fried ones, and try to avoid things coated in cream, butter or mayonnaise. While you're at it, skip the salt; it has been shown to cause blood pressure to spike.

3. Kick the smoking habit
If you needed any more reasons to stick to your New Year's resolution to put down the pack, puff on this: Cigarette smokers are two to four times as likely to develop coronary heart disease and 10 times as likely to develop peripheral vascular disease as nonsmokers, according to the CDC. What's more, cigarettes compromise a healthy heart by approximately doubling a person's risk for stroke.

4. Brush and floss
A study conducted by scientists at Howard University found that people suffering from chronic periodontitis, a disease marked by inflamed gums and deep pockets between the gums and teeth, were more likely to develop coronary heart disease, perhaps due to bacteria associated with gum disease entering the bloodstream.

5. Soak up the sun — safely
A recent article in Circulation, a medical journal published by the American Heart Association, linked vitamin D deficiency to heart disease. As scientists already know, too little time spent in the sun (along with a diet lacking in the nutrient) contributes to low vitamin D levels. The study found that sun-deprived patients with heart disease were 30% to 50% more likely to suffer severe disease or die. Some amount of sun is healthy for your heart, but before you hit the beach, always make sure to apply sunscreen with a high SPF, as sunbathing carries the risk of skin cancer.

6. Keep your cool
Like smoking, stress can increase your risk for high blood pressure and heart disease. Though more research is needed to pinpoint the ways in which stress affects cardiovascular health, it is known that stress hormones increase the level of cortisol, a "feel good" chemical that repairs inflammation but has been linked to higher blood pressure. Working out is a great way to blow off steam, keep your cortisol count in check and your heart healthy.