By Jonty Skinner and Phillip Whitten

The Ideal Swimmer’s Body
Do you have a body that can help make you an outstanding swimmer? Until genetic engineering can supply you with gill slits and flippers, you’ll have to work with the physical characteristics that can contribute to swimming success.

It’s pretty hard to miss. Turn on the tube to watch the Olympics, World Championships or any major meet and you’ll notice that the winners tend to look alike: long, lean and supple.

That’s especially true of sprinters: world record holder Alex Popov is 6-7, as is former world record holder Matt Biondi. Gary Hall, Jr. and Sabir Muhammad both stand 6-6. So does Pieter van den Hoogenband, the Dutch swimmer who dethroned Popov in the 50 and 100 freestyles at the recent European Championships.

It tends to be true of middle-distance and distance swimmers as well: Aussie teen sensations Grant Hackett and Ian Thorpe are 6-6 and 6-5, respectively.

The top women also fit this profile: Amy Van Dyken, a quadruple gold medalist at the Atlanta Games, and Inge DeBruijn, the world’s fastest sprinter the last two years, are both about 6 feet. Kristy Kowal, the American record holder in the 100 and 200 yard breaststroke, is 6-1.

At the Masters level, we tend to see the same thing: the long, lean sprinting machines among us—of whatever age—often wind up atop the victory least for the freestyle and backstroke sprints.

But if we look a little closer, things become a bit more complicated. The greatest female distance swimmer in history was Janet Evans, who stood 5-5 when she set her still-standing world records in 1988 and ‘89. The greatest backstroker in the world today, Lenny Krayzelburg, stands 6-3, but he is more heavily muscled than Popov, Hall or the Dutchman, “Hoogie.”

In Masters swimming, one of the most dominant breaststrokers of any age is 53-year-old, 5-10, Bob Strand; Nancy Ridout, the top sprinter in the women’s 55-59 division, is barely pushing 5-2. So factors other than height and leanness can contribute to swimming success.

My research at the U.S. Olympic Training Center in Colorado Springs has identified several of these factors: center of mass (COM), body density (DEN), physiology, anthropometry, hull length and shape, strength profile, leg power and feel for the water. Two other factors are also significant, especially for Masters swimmers: flexibility and percent body fat. Let’s look at each of these.

Center of Mass (COM)

Every athlete has a balancing point in the water. The closer the COM in the body is to the center of flotation (the lungs), the easier it is for the body to float horizontally with little or no effort on the part of the athlete.

The opposite puts the athlete at a serious disadvantage since he will have to work hard at balancing the body and offset the torque created by the legs as they naturally want to sink to the bottom of the pool.

Body Density (DEN)

This is a combination effect of the lung capacity, and the muscle and bone density of the athlete. Some athletes float easily on top of the water, while some sink like a rock. (To test your buoyancy, see Scott Rabalais’ article, “Buoyancy: Float Like a Pull Buoy” in the May/June 1999 issue of SWIM.)

Like high COM athletes, those with a low density (floaters) are able to consider a broad range of events, while those with high density (sinkers) are somewhat limited to the sprints.

Since these two elements go hand-in-hand with one another, I have developed a simple table that identifies six zones. In Zone 1 are the high COM, low DEN swimmers—balanced floaters. Janet Evans almost certainly was a Zone 1 athlete. At the other end of the scale are the Zone 6 swimmers—with low COM and high DEN, they are the leg-sinking sinkers.

If you fall into Zones 1 or 2, look at additional factors to determine your race potential. If you fall into Zones 5 or 6, you’ll need to have additional qualities—such as leg strength—geared toward the sprint events in order to swim fast.

If you score in Zone 6 and have a high number of slow-twitch fibers, you can still be a distance swimmer, but don’t expect to set any records.


Here, physiology refers to the muscle fiber makeup of the athlete: specifically, the balance of slow-twitch (ST) and fast-twitch (FT) fibers. Actually, there are two kinds of fast-twitch fibers: a and b. FTa are those fast-twitch fibers that can be recruited to either aerobic or anaerobic training. FTb are geared toward anaerobic conditions.

The athletes with the greatest potential in the sport of swimming are those with the greatest number of FTa fibers. They have a potential to swim a wide range of events and can possibly offset any shortcomings in the areas of COM/DEN. Mark Spitz and Tracy Caulkins probably had unusually large numbers of FTa fibers, which would account for their versatility.


Limb length and size play a huge role in event potential, and the relationship between arm length and height gives a better picture of the athlete’s potential. Swimmers with a high anthropometry score—that is, their arms are relatively long in relation to their height—tend to do best in the long-axis strokes, freestyle and backstroke. Swimmers with lower scores tend to excel in the short-axis strokes, breaststroke and butterfly.

Most measurements are related to height since the length of the “hull” limits an athlete’s potential velocity.

Hull Length and Shape

Bill Boomer has likened the swimmer’s body to a ship’s hull. The longer the hull, the faster the swimmer’s potential speed. The wider the hull, the greater the potential for passive drag, thus putting the brakes on the swimmer.

Strength Profile

Some athletes are born with natural strength, while others have to work very hard to achieve the same level of strength. Elite swimmers with natural strength are able to work hard in the weight room with little effect on in-water training, and can reduce weights three to six weeks out of their major meet while maintaining their strength and power.

Swimmers with less natural strength find that weightlifting has a large effect on their in-water training, and that they tend to lose the strength they’ve gained very quickly. So, elite swimmers of this type need to maintain work in the weight room up to 10 days prior to the event.

As a Masters swimmer, try experimenting with differing lengths of rest before your big meet, to see how long you should continue lifting. In general, swimmers with less natural strength would probably be better off gearing their training toward cardiovascular fitness.

Leg Power

In long-axis strokes, leg power can be used for rotation assistance or balance, and it can contribute significantly to forward propulsion. This propulsion can offset some limitations in COM/DEN, so leg power should be taken into account when determining your ideal events and strategy.

In short-axis strokes, leg power is even more crucial. Most of the propulsion in breaststroke comes from the legs.

Feel for the Water

Feel is practically impossible to measure, but it is still important in the assessment of any swimmer. Troy Dalbey has written about developing a good feel for the water (see “What about Feel? The Art of Staying Relaxed” in the July/August 1998 issue of SWIM.)

To some degree, leg power can offset limited feel, but a swimmer with poor leg power and poor feel has no choice but to follow the cardiovascular route to success.

Some Examples

Amy Van Dyken is a Zone 1 athlete—a balanced floater—with mostly FTb muscles. Though she’s tall, her arms are relatively short, and she doesn’t have great leg power. To succeed, she needs to build up strength both in her arms and legs. Her best events clearly are sprints.

Sabir Muhammad is off the charts on every anthropometric measurement there is: he’s tall (6-6), has extremely long arms, and very big hands and feet. His lung capacity is the second highest we’ve measured in any sport at the Olympic Training Center—butterflyer Tom Malchow is first.

But Sabir is a rock. And he has a low COM. His whole body sinks—legs first—and stays at the bottom of the pool. You don’t get any more Zone 6 than Sabir.

On the other hand, his physiology is great—almost entirely FTa muscles. So Sabir can be competitive up to 200 yards (short course). But his energy cost for 200 meters (long course) is far too great. He, too, should focus on distances of 100 meters or less.

Lenny Krayzelburg is almost ideal. He’s Zone 2 all the way—a balanced floater. His pluses include a preponderance of FTa muscles, great anthropometry, a terrific strength profile, extraordinary strong legs and a training program (under Coach Mark Schubert) that suits his strengths and needs. On top of that, he has a fierce work ethic and desire to win. These strengths offset a hull size that is too broad and a low center of mass. Still, from a physical standpoint, Lenny has just about everything going for him.

Other Factors

Two other important factors are flexibility and percent body fat. The best swimmers are extremely flexible—Mark Spitz used to touch his elbows to the ground without bending his knees—and work hard at becoming even more flexible. As people age, they tend to become stiffer and less supple. One of the best guarantees for your success in Masters swimming is to maintain or increase your flexibility through stretching exercises.

If you carry extra body fat, swimming is more forgiving than land-based sports. But to enhance your swimming potential, it’s important to maintain a low percentage of body fat: no more than 15 percent for men and 22 percent for women, regardless of age.

So, having the right genetic makeup—tall, long limbs, big hands and feet, low density, high center of mass, a preponderance of FTa muscles, and natural strength—can give you a head start on becoming an outstanding swimmer.

Fortunately, anatomy is not necessarily density—especially at the Masters level. You can improve your balance, fine-tune your cardiovascular system, increase your strength (particularly leg strength), work on stroke technique, enhance your feel for the water and stay lean and supple as you get older.

You can’t choose your body, but you can work with your natural endowments. And you can use the information in this article to choose the best events for you.

About the Author
Jonty Skinner is the technical advisor of SWIM Magazine and the head coach of the U.S. National Resident Team in Colorado Springs, Colo. Phillip Whitten is the editor-in-chief of SWIM.