Harvard Heart Letter

Take the plunge for your heart

You don't need to be a Pisces for your heart, and the rest of you, to reap the benefits of swimming.

Any kind of exercise is better for your heart than no exercise at all. Walking is often held up as the gold standard — most people can do it, it's easy on the body, and it doesn't take any special equipment or venue. Walking isn't necessarily the best exercise for the heart and general good health, but it's the best option for the greatest number of people.

More vigorous activities do even more for the heart than walking. The lion's share of research has focused on running, because it's a logical extension of walking and because it's a fairly popular form of exercise. Swimming, by comparison, has been a backwater of exercise research, with barely a trickle of studies over the years on swimming and heart disease. Two new studies from the Cooper Clinic in Dallas highlight the health benefits of swimming.

One study compared blood pressure, cholesterol levels, maximum energy output, and other measures of cardiovascular health across nearly 46,000 male and female walkers, runners, swimmers, and couch potatoes. Swimmers and runners had the best numbers, followed fairly closely by walkers. As you might expect, nonexercisers had the highest weights and resting heart rates and the worst cholesterol levels and overall fitness.

The second study looked at deaths among 40,547 men ages 20 to 90. Over an average of 13 years of follow-up, only 2% of the swimmers died, compared with 8% of runners, 9% of walkers, and 11% of nonexercisers. Both studies were published last year in the International Journal of Aquatic Research and Education.

All-over workout

Swimming works the heart and lungs. This trains the body to use oxygen more efficiently, which is generally reflected in declines in the resting heart rate and breathing rate. It uses the arms, the legs, and other muscle groups in between. This improves muscle strength and flexibility.

Water supports and cushions the body, eliminating the kind of pounding associated with running. Because it's easy on the joints and muscles, swimming is often recommended for people with arthritis and other chronic conditions. The resistance of water also allows you to work out vigorously with little chance of injury.

There's also a relaxing, meditative side to swimming. It can come with letting your mind drift as, bathed by soothing water, you focus on your breathing and your movements. This stress-busting aspect could contribute to the cardiovascular benefits of swimming.

Best of all, swimming is the kind of activity you can do across the life span, and needn't give up late in life.

Jump in, the water's fine

If you're already a swimmer, you've discovered the benefits of this activity. If you aren't, it's never too late to learn how to swim or to brush up on strokes you learned as a kid.

If you're a beginner, or are getting back into swimming, start slowly with five to 10 minutes of smooth lap swimming. As you get used to the exercise, and your strokes, kicks, and breathing become more efficient, you'll be able to swim for longer periods. Mix up your strokes — freestyle, backstroke, butterfly, whatever you can do. In addition to keeping your swimming routine fresh, the variety helps you work different muscles.

If doing laps isn't your thing, there are excellent aquatic alternatives to swimming. Try walking or running in water. It is far easier on the joints than walking or running on land, but offers an equally good cardiovascular workout. Another option is water aerobics. This type of exercise is a staple at many community centers, YMCAs, JCCs, and other facilities with pools.

The "best" sport?

If you could pick one sport early in life that would carry you through to a healthy old age, what would it be? Tennis, says a study that followed a thousand medical students for 40 years. The doctors in training who played tennis were more likely to stick with their sport as they aged than those who played baseball, basketball, or football. They also had lower rates of heart disease.

It's a cute finding, and makes some sense. Tennis can give your heart a good workout. It's a sport that can be played at many different levels. And, like swimming, tennis is something you can continue doing into old age.

The reality, though, is that any sport or exercise program that helps you be active most days of the week is the best one for you, whether it's walking, swimming, tennis, rowing, bicycling, or whatever else gets you moving.

It's not your one and only

Although swimming can be great for the heart, lungs, blood vessels, and muscles, it doesn't do much for the bones. That's why swimmers need to supplement their aquatic training with some weight-bearing exercise, like strength training, walking, dancing, stair climbing, or gardening.