One of the best workouts for your heart

Any form of aerobic exercise, such as walking, running, biking or swimming, can improve your cardiovascular fitness. Interval training — alternating short bursts of high-intensity activity with less intense activity — is especially effective. Here's why:

• Interval training challenges your heart by putting it into the maximal heart rate zone for short bursts of time. The maximum heart rate is the upper limit of what your cardiovascular system can handle during physical activity — an intensity that feels like you're working very hard.
• Between the high-intensity intervals, your heart rate comes back down into a lower heart rate zone, allowing for heart rate recovery.
• Getting your heart rate back up after a short rest challenges your heart muscle in a way that makes it operate more efficiently.

How does interval training work? Here's a sample 40-minute exercise session that includes interval training:

1. Walk slowly to warm up. Gradually increase to a moderate pace for five minutes.
2. Increase your speed so that you're walking briskly.
3. After five minutes of brisk walking, increase your speed so that you are jogging for 30 seconds to two minutes.
4. Slow down to walking a moderate pace for one to three minutes.
5. Repeat steps 2, 3 and 4.
6. After 35 minutes, walk at a slower pace for five minutes to cool down.

If you have a chronic health condition or haven't been exercising regularly, consult your doctor before trying interval training. The American College of Sports Medicine recommends that people have established a base level of fitness — exercising three to five times a week for 20 to 60 minutes — before beginning interval training.

Resistance training, also called strength training, has benefits for your heart, too. Long-term resistance training can help lower blood pressure. Resistance training also increases muscle mass. This makes it easier for your body to burn calories and maintain a healthy weight, which helps keep your heart healthy.