Becoming a Lean Mean Swimming Machine

Or not

Have you ever noticed that swimmers may not have the leanest bodies, when compared to runners, cyclists or triathletes?  In fact, being "lean" may actually hinder performance.  In this article, we'll take a look at body fat and how it might affect swimming performance.

Body Fat Defined

The body requires a certain amount of fat for normal organ function.  This is called essential fat.  It is stored in small amounts in the bone marrow, organs, central nervous system, and muscles.  Women, typically have more essential fat (sometimes called sex-specific fat), found in the breast, pelvis, hips and thighs, which is essential for child-bearing and normal reproductive function.  

Essential fat plus stored fat is called total body fat.  Storage fat is found under the skin and in and around the muscles and organs.  A certain amount of storage fat is desirable as this kind of fat provides "cushion" to the organs and bones to protect from injury.  The following table shows the various classifications of body fat for most individuals, and for certain athletes.

Classification	Men	Women
Essential Fat	3%	12%
Athletic	5-10%	8-15%
Good	11-14%	16-23%
Acceptable	15-20%	24-30%
Overweight	21-24%	31-36%
Obese	>24%	>37%
Runners	5-11%	10-15%
Cyclists	5-15%	15-20%
Triathletes	5-12%	14-24%
Elite Swimmers	6-12%	14-25%
Masters Swimmers	10-20%	15-25%

Fat Swimmers Are Good Swimmers

There are several reasons why swimmers may never get as lean as cyclists or runners, and there are further differences between men and women.  Thermodynamics may play a role.  Since the water temperature of a pool is 15-20 degrees below the body's temperature, there is a natural "cooling effect", which may lower caloric burn as compared to runners and cyclists who get heated during workouts and potentially burn more calories.  Women, in general, have a higher body percentage of body fat than men, giving them a buoyancy advantage. Additionally, a woman's fat tends to be distributed more heavily in the lower half of the body, giving lift to the legs, reducing body drag.  As a result, the amount of energy required for a woman to swim at the same pace as a thin man is significantly less.

Deciding How Much and When to Lose Weight

Swimmers will want to be careful when trying to become a lean mean swimming machine.  Losing too much fat may negatively affect performance by requiring a higher energy expenditure for the effort spent.  A serious swimmer should perform a test set every 3-4 weeks when losing weight.  The test set should compliment the swimmer's strength, whether it be sprinting or endurance.  Attention should be given to effort as measured by heart rate, perceived exertion, and time/splits.  Recording weight and body fat will help determine when optimal body composition is attained.  Finally, weight training to improve strength may also affect performance both positively and negatively.  While strength training will improve a swimmers ability to sustain performance, too much lean muscle mass, at the expense of fat, may "sink" a good swimmer.

Determining when to lose weight may be just as important as how much to lose.  It is suggested that changes in body composition occur in the early stages of training, while building endurance and strength.  It is not advised to change body composition within 8 weeks of "A" focus races, like state or national competitions.  The risks of losing strength and body fat, and negatively affecting energy expenditures while training may be too great.  Weight loss and "leaning up" should cease at the point of "diminishing returns" if performing test sets during the endurance and strength phases of training.

Good luck swimming, love your body no matter what shape, and happy laps!

Kathy

Kathy Kent is a nationally acclaimed speaker on health and fitness issues.  Her company, 365fitt, provides consulting and training services to corporations, communities and individuals seeking a healthier lifestyle.  Her book, Living 365fitt, A 12-Week Program to Lifestyle Wellness, and accompanying webinars, provide sound information on physical, nutritional and emotional lifestyle changes for better fitness.  

Contact Kathy for more information at kathy@365fitt.com.