Swimming For Your Life

小臭贝

Deep down, we always knew it was true.

Okay, okay.  We hoped it was true.

And with good reason.  After all, it makes perfect sense.  Most scientific experts, from exercise physiologists to gerontologists, have long acknowledged that swimming is the best all-around form of exercise you can do to maintain optimal cardiovascular and muscular strength.

Why?

1. It works all the muscles of the body, unlike running, cycling, tennis and virtually every other form of exercise you could name.
2. What's more, since the sport takes place in water, it is very low-impact.
3. That means that swimmers sustain far fewer injuries than, say, runners, and spend much less of their time recuperating from the injuries they do sustain.
4. It also means that swimming truly is the ideal sport for a lifetime.  There are very few octogenarian linebackers, wrestlers, shot putters, kick-boxers, hockey or even baseball players.  But there are tens of thousands of men and women in their eighties, nineties and older who maintain extraordinary fitness by swimming three, four or five times a week.
   
Since swimmers are able to maintain a high level of fitness, it makes sense that they would also live longer than both their sedentary friends and those who run or do another form of exercise to stay in shape.  But where was the proof?

Then, there were always the doubters, not to mention the folks who asked uncomfortable questions, questions that made you squirm. What was the effect of immersing yourself, day after day, year after year, in chlorinated water? What kind of risk did you take by swimming alone on occasion, without a lifeguard?  Or, turning it around, could you push yourself too hard training with a Masters team, trying to hang with that cute 35 year-old in the next lane, and wind up with a heart attack?  And what about drowning?  Or getting eaten by a shark?

Still, it made sense.  If swimmers were healthier and more fit than couch potatoes and even runners, wouldn't they live longer?

This is, after all, a question of intense personal interest to hundreds of thousands, perhaps millions of people.  So it is strange that researchers would avoid looking into the matter and trying to answer the question.

Until now.

Recently, a 13-year study led by Steven N. Blair of the University of South Carolina, compared the mortality rates of runners, walkers, sedentary folks and swimmers.  In 1995, Blair and his associates carefully scrutinized data on 40,547 men from 20 to 90, who were patients at the famed Cooper Clinic in Dallas, Texas.  The men were then divided into groups based upon the type of exercise (if any) they did: 15,883 were deemed to be couch potatoes; 20,356 were classified as runners; 3,746 were walkers; and 562 were swimmers.

Over the next 13 years, some 3,386 of the Cooper Clinic patients died.  Just who  was most likely to have died was quite predictable.  The highest death rate occurred among the sedentary group: Eleven percent (1,747) of the couch potatoes passed away.  In contrast, 7.8 percent of the walkers (292) and only 6.6 percent of the runners (1,336) died.  None of this raised any eyebrows.

What did jump off the page, however, were the data for the swimmers.  Only 1.9 percent of the swimmers – 11 individuals – died during the 13 years of the study.

Why did swimmers have such a low mortality rate?  Professor Blair and his colleagues did not offer any hypotheses, noting that swimmers tended to have a higher BMI (body mass index) than the runners and higher fasting blood glucose levels.  On the other hand, their total cholesterol numbers were lower while their HDL (good cholesterol) scores were higher.  My guess is that these differences are probably irrelevant.

Though follow-up studies – with larger numbers of swimmer subjects – undoubtedly need to be done, the message from the research lab is clear: keep on stroking, baby.  You literally are swimming for your life.