UW Health Sports Medicine Center weighs in on body fat

How low can you go…safely?

Thanks to a landmark study involving the UW Health Sports Medicine Center, physicians and coaches can evaluate the effectiveness of methods widely used to measure body composition and predict the minimum weight an athlete should maintain.

Using a four-component model that included independent assessment of bone, body fat, muscle and total body water, 53 Division-I collegiate athletes were measured, yielding a precise reading that allowed for the accurate prediction of a minimum weight. The study was conducted in response to a call by the National Federation of State High School Associations (NFSHA) mandating that all states develop a minimum-weight certification program modeled after the one established by the Wisconsin Interscholastic Athletic Association (WIAA) in 1993. The findings appear in a recent edition of Medicine & Science in Sports & Exercise, the journal of the American College of Sports Medicine.

More than just a topic for exercise scientists, the issue of minimum weight prediction closely affects high school and college athletes, particularly wrestlers. In recent years, several athletes have died–including three wrestlers in a span of 33 days in 2003–after using unsafe weight loss practices in order to compete in a lower weight class. But Randy Clark, the manager of UW Health Sports Medicine’s Exercise Science Laboratory and the study’s first author, says the findings also have important implications for the national fight against pediatric obesity.

“Body composition has never been a more important issue than it is today,” says Clark. “It’s always been an important component when evaluating athletes, but it’s equally important for this generation of children. This is the first generation in history that will have a shorter life expectancy than that of their parents. Reduced activity, excess body fat and excess body weight are important factors bringing about this sad fact.”

For years, physicians have used the body-mass index (BMI) to roughly gauge body composition, assigning individuals a number based on a ratio between height and weight. Clark hopes that an actual measure of body composition will soon become an important component of everyone’s physical exam, not just athletes.

UW Health Sports Medicine is also involved in a new research study called Fit-4-Life. The program has shown positive changes in body composition, fitness level, and insulin sensitivity using a lifestyle-focused physical education curriculum for students at River Bluff Middle School in Stoughton.

“We are applying ideas and concepts previously reserved for elite athletes to children, particularly a new generation of kids who are struggling with weight issues,” says Clark. “They love it. They feel like heroes, and it’s the first time they have enjoyed a physical education class. Parents thank us for changing the dynamics of their family and making physical activity fun again. This is every bit as rewarding as our work with major college athletics.”

UW Health Sports Medicine was instrumental in developing both the Fit-4-Life program and the minimum weight standards used by the NCAA, WIAA and NFSA. Under the new guidelines, the more than 10,000 male high-school wrestlers in Wisconsin (and 100,000 nationally) must maintain at least 7 percent body fat, while college-level wrestlers must maintain at least 5 percent.

“Eventually these minimum weight standards may be adopted by other sports where leanness is a concern, like track and field, cross-country, lightweight rowing, gymnastics and ice skating,” says Clark. “Too little body fat and too much body fat are both serious medical concerns.”