Here about benefit of swimming.
When it comes to heart health, nearly all kinds of exercise are helpful; the trick is to do enough (30 minutes or so of moderate activity) often enough (nearly every day). Walking is often held up as the gold standard -- most people can do it, it's easy on the body, and it doesn't require any special equipment beyond a good pair of walking shoes. Walking isn't the only way to protect your heart and improve health, but it's the best option for the largest number of people.
More vigorous activities will improve health in less time 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 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. But a study published last year highlighted the health benefits of swimming.
Researchers 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, people who didn't exercise had the highest weights and resting heart rates -- and the worst cholesterol levels and overall fitness.
What makes swimming so beneficial? For one thing, it gives the heart and other muscles a solid workout. This trains the body to use oxygen more efficiently, which helps bring down the resting heart rate and breathing rate. And because you use your arms, legs and all the muscle groups in between, swimming improves muscle strength and flexibility.
Water 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 who have arthritis and for those who are overweight. 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 you focus on your breathing and your movements. This stress-busting ability makes the list of swimming's cardiovascular benefits even longer.
Best of all, swimming is an activity you can do across your life span, and you needn't give up it late in life. And it's never too late to learn how to swim or to brush up on strokes you learned as a child.
If you're a beginner or are getting back into swimming, start slowly with five to 10 minutes of smooth lap swimming. (For safety's sake, never swim alone.) 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 you tire of doing laps, 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, schools and other facilities with pools.
Although swimming (and cycling, for that matter) can be great for the heart, lungs, blood vessels and muscles, your friend is right that it doesn't do much for the bones. While most body systems receive the maximum health benefit from aerobic forms of activity, bones are different. Stress, in the form of weight-bearing exercise, is necessary to stimulate the growth of new bone.
Any activity that works against gravity -- running, walking, playing soccer, weight lifting or dancing, for example -- can help build bone. Even daily activities such as stair climbing help, so you don't necessarily need to cut down on your swimming to fit weight-bearing exercise into your schedule. Talk to your doctor about what combination of activities makes the most sense for you.
One final note: Water leaches natural oils from your skin and hair, and chlorine compounds the problem. Wear a cap while you swim. Afterwards, wash your hair with a clarifying shampoo and apply a conditioner; look for products designed for use after sun or pool. Use a body wash or soap with bath oil, and then apply generous amounts of moisturizing body lotion. That way, you'll not only feel good, you'll look good, too!