Published 9/1/2013
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Mary Ann Porucznik
Today’s football players are big. According to Letha Y. “Etty” Griffin, MD, between 1924 and 1980, there were never more than eight National Football League (NFL) players who weighed more than 300 pounds. But a 2009 study of NFL rosters found 343 players who weighed more than 300 pounds.
“We have made an epidemic of big people—not only tall players but heavy players as well,” said Dr. Griffin, who addressed obesity in athletes during the 2013 AAOS Now forum on “Obesity, Orthopaedics, and Outcomes.” And the epidemic isn’t limited to the pros; just last year, a Pee Wee football league in Texas banned a 297-pound, 12-year-old boy from participation, citing safety concerns for players who generally weighed l00 pounds or less.
But, asked Dr. Griffin, “Are players heavier because of unessential fat or lean body mass? Are we building a monster?”
Matching body types to sports
“Body composition cannot predict success in sports, but it can predict optimum performance,” noted Dr. Griffin. Power athletes are strong, powerful, and often large. Endurance athletes are also strong, but leaner. And many sports require a balance between the two body types.
“Fat can be an asset when big is advantageous but agility is not a necessity,” said Dr. Griffin, pointing to the differences between defensive linemen, offensive linemen, and running backs. “Big is better if you’re a lineman because you need power, but not speed.”
But weight gain must be controlled and nutritionally supported. “It takes 1.2 grams of protein per kilogram of body weight to maintain muscle mass for sports,” noted Dr. Griffin. “But if you want to lose fat, you’ll need to bump that protein level to 1.5 g/kg, and if you want to build muscle, not fat, you’ll need to bump it again to 1.7 g/kg.”
According to Dr. Griffin, players need individualized weight management plans and goals—beginning in high school. Otherwise, metabolic syndrome—a combination of medical disorders that increase the risk of cardiovascular disease—may develop (Table 1).
She also noted the difficulty obese athletes have in dissipating heat, which increases the risk of heat disorders. “Increased body mass leads to relatively low surface area necessary for heat dissipation. Fat is insulating and the amount of metabolic heat production increases with body weight,” she said. “That’s three strikes against them.”
Metabolic issues remain important even after an athlete’s playing career ends. “The two most significant factors that predispose former athletes to heart disease are body weight and exercise habits,” said Dr. Griffin. “When their playing careers are over, many athletes don’t continue an active lifestyle; they don’t put out the amount of energy that they did while playing. But their eating habits were established when they were playing, and that creates problems.”
Dr. Griffin urged physicians who specialize in sports medicine or who serve as team physicians to work with athletes, particularly at the college level, to enable them to transition to healthy weight management. “This group is different than other overweight adults. You can help them develop a program of diet and exercise maintenance to transition their lives after college and they’ll follow your advice.”
Fit is the new skinny
College athletes aren’t the only ones who need nutritional advice, cautioned Vonda J. Wright, MD, MS. “We’ve got an entire generation of obese children trying to play T-ball. We’ve got the traditional athletes who are bigger, but not necessarily leaner. We have masters athletes—those older than age 40—who are the largest growing active group in this country.”
Dr. Wright noted that athletes come in all shapes and sizes—depending on their sport and their fitness level. “Fit is the new skinny,” she said. “The very thin experience the same type of metabolic problems that the obese have, and some people can be profoundly overweight by standard measures and yet be happy inside because they are fit.”
When it comes to fat, said Dr. Wright, “location matters.” She noted that genetics accounts for only about 30 percent of an individual’s total health profile; the rest is due to lifestyle choices. “That’s a profound statistic,” she said, “because it puts individuals in control of what they are.”
Although obese athletes are less likely to smoke and have high muscle strength, greater aerobic capacity, and a decreased prevalence of impaired glucose metabolism compared to people who have never been athletic, obesity presents the same problems for athletes as for the normal population.
“It takes a lot more work to perfuse fat,” said Dr. Wright. “Thirty pounds of excess weight means 25 miles of additional capillaries and a lot of extra work for the heart.”
Children who are obese, even if they are active, are at increased risk for injury during sports, noted Dr. Wright. “They’re big, but they’re not strong, don’t have high levels of muscle mass, aren’t well coordinated, and are subject to high shear forces. In addition, they have impaired postural control due to the imbalance between weight and height. And obesity in children causes increases in proinflammatory cytokines and inhibits anabolic hormones associated with growth because most kids don’t exercise intensely enough.”
Dr. Wright also raised the issue of whether young, obese athletes might require medical clearance before undergoing surgery. “At my institution, the criteria for preoperative clearance for athletes is age-related (older than age 40), unless the patient reports a previous medical problem. But because most youths don’t get enough medical care, we might want to consider establishing a weight standard for preoperative clearance,” she said.
“Body mass index (BMI) isn’t the issue; body composition management is,” said Dr. Wright. “As physicians who treat athletes, we need a paradigm shift in thinking. Our patients aren’t all athletes like Tim Tebow; some of them are children, some are high school or college players, and some are masters. We’ve got to do more research and work with them.
“It takes time. It takes a program—meetings, nutritional counseling, mental coaching, physical therapy, maybe even a little hand-holding—but we’ve got to do something. Get people off the couch and into the pool. They don’t have to swim; they can burn calories simply by walking in the pool. Tell them to stop eating salad dressing, gravy, and fried foods; that alone will eliminate 1,000 calories a day for most people.
“If we tell adults to stop doing something because it hurts, without giving them modifiable ways to stay active, we are sentencing them to ‘sedentary death syndrome.’ We’ve got to be better than that,” urged Dr. Wright.
The AAOS Now forum on “Obesity, Orthopaedics, and Outcomes” was held on March 18, 2013. For a copy of the agenda book, including selected study abstracts, email aaoscomm@aaos.org
Mary Ann Porucznik is managing editor of AAOS Now. She can be reached at porucznik@aaos.org
Bottom Line
- The concern about obesity in athletes has gained momentum as the size of power athletes has increased.
- Fitness—regardless of body size—is more important than weight for metabolic health.
- Sedentary death syndrome can be avoided with a regular program of exercise and diet.
- Body composition is more important than body mass index in determining metabolic health.
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