Cerny and Paula Maxwell, his doctoral student, keep their eyes glued to a tank-side monitor until it registers Jeff's weight under water, then signal him to surface.

The procedure is called hydrostatic weighing, the most accurate method of determining body composition.

IN THE TANK: Jeff Zoerb, a Wilson High School wrestler, lies in tank for hydrostatic weighing by Frank Cerny, chair of Physical Therapy, Exercise and Nutrition Sciences, and doctoral student Paula Maxwell.

Jeff, who will repeat the exercise 10 times before he climbs out of the tank, is at UB complying with a new rule instituted by the New York State Public High School Athletic Association, Inc. The regulation mandates that all wrestlers must be assigned a minimum weight class, tied to percent of body fat, in order to compete in the 1997-98 season.

UB is one of only two sites‹the other is Adelphi University on Long Island‹certified by the association to conduct hydrostatic weighing for high-school wrestlers.

Certifying each wrestler at a minimum weight class is intended to eliminate interscholastic wrestling's time-honored, but health-threatening, practice of "making weight," the process of trying to lose pounds rapidly to qualify for a lower weight class in hopes of gaining a competitive advantage in a particular match. Wrestlers will starve themselves, take no liquids and push themselves through punishing workouts to accomplish this.

Sometimes the sacrifice pays off; sometimes it costs dearly. A University of Michigan wrestler collapsed and died Dec. 9 in the midst of a two-hour workout wearing a rubberized wet suit in 92-degree heat. The medical examiner ruled death was caused by excessive training while trying to lose too much weight too fast. Two other college wrestlers have died under similar circumstances since Nov. 7.

"Making weight" is seldom fatal, but everyone associated with the sport of wrestling agrees the practice compromises the health of young athletes. "Wrestlers may binge-eat and then purge, which prevents them from getting enough nutrients," Cerny says. "They dehydrate themselves to lose water weight, which puts a lot of stress on the cardiovascular system."

Under the new regulation, a wrestler's minimum weight class is tied to percent body fat‹in this case 7 percent‹the minimum percent body fat considered healthy for growing athletes. Wrestlers with less than 7 percent body fat must use their actual weight, as determined by an accredited assessor, as the minimum weight at which they can compete. Wrestlers with 7 percent body fat or more must compete at the higher of the two weight classes between which their actual weight falls.

Body-fat content traditionally is determined by the skin-fold test, in which a trained assessor uses special calipers to grasp a portion of flesh, usually at the waistline. Established equations convert the amount of subcutaneous fat into percent of body fat. Wrestlers who dispute the skin-fold result may elect to undergo hydrostatic weighing. About a dozen wrestlers from Central and Western New York have gone through the process at UB so far. Hydrostatic weighing to certify wrestlers is an exacting process. The athletes first must undergo urinalysis to detect dehydration, a traditional method of quick weight loss. If the specific gravity of urine is too high, body-fat testing is postponed for at least 24 hours.

Jeff passes the urinalysis, so the next step is to measure his residual lung volume‹the amount of air left in the lungs after exhaling. It is de- termined by inhaling deeply and exhaling completely into a spirometer, a device for measuring air entering and leaving the lungs. Jeff repeats the process several times. The highest result will be used to help determine body density underwater: Apparently, even air weighs something.

Clad in swim trunks, Jeff showers to remove all air from his hair and trunks, which could skew the underwater results, then climbs into the immersion tank. After making sure Jeff can handle being submerged and breathless, Cerny proceeds with the weighing.

The average of 10 acceptable readings, along with residual lung volume and other variables, will be inserted into a standard equation used to determine body density, which will be part of yet another standard equation to convert body density into percent body fat. The final figure is mailed in a sealed envelope to the high school athletic director.

New York is one of only three states‹Wisconsin and Michigan are the others‹that have instituted a minimum weight certification requirement for high-school wrestlers. New York's program includes a nutrition education workshop. True believers in the positive long-term effects of leanness, Cerny and the department are offering hydrostatic weighing to all individuals interested in finding out their percent of body fat.

Hydrostatic weighing, which takes about 15 minutes and costs $20, is being offered through the department's Exercise Science Program. For an appointment, call 829-2941 ext. 404.