A Sporting Chance : You may not have been a Michael Jordan or Martina Navratilova as a child. But your kids can trump the genes they’ve been dealt.

Suppose you are the most uncoordinated person in California.

And suppose the most athletic thing your spouse has ever done is drift-boat fishing.

Does this mean your 8-year-old child is destined to a lifetime of Nintendo and being the last kid picked for kickball at recess?

Not necessarily. But a new study--sure to dishearten some parents--points to heredity as a strong determinant of physical fitness and athleticism.

In the study of 105 pairs of 10-year-old twins and their parents, researchers found that fitness scores on such tasks as arm strength, jumping ability and aerobic capacity were remarkably similar between parent and child.

“What is clear is that genes have something to say, and they will determine what range [of fitness] you can expect yourself to end up in,” says Hermine H. Maes, a geneticist who conducted the study in Belgium. “If you want to be a top athlete, for instance, you had better have a pretty good set of genes.”

Using an intricate mathematical model that considered both genes and environment, the researchers concluded that heredity contributed to:

* Three-quarters of a child’s ability to pull weights with the arms and do bent-arm hangs.

* Two-thirds of a child’s vertical-jumping ability.

* Two-thirds of the ability of male children on aerobic capacity tests; almost 90% in female children.

The study was published this month in Medicine and Science in Sports and Exercise, a journal of the American College of Sports Medicine.

The researchers cautioned that the study only predicts the likelihood that a child will be predisposed to physical prowess. It nevertheless raises very practical questions about how to promote fitness and athletic endeavors among the children who may be destined to find soccer, softball, ballet or even P.E. class difficult and frustrating.

“There are definite health benefits to being fit. And if genes play a huge role, what does that leave for those not born with the genes that make you fit?” Maes notes.

Indeed, the study and others like it may shed some light on why so many families encourage their young children to participate in sports only to see them drop out soon thereafter, frustrated and embarrassed by their lack of ability.

According to one study, about 20 million school-age children enter organized youth sports each year in the United States. But by age 13, according to a Michigan State University study, the vast majority of them have dropped out. Besides stating that the activity wasn’t fun, a majority of the kids surveyed said they quit because they lacked the ability to perform.

Another study by researchers at Northern Kentucky University also highlighted the problem of expecting too much from unathletic children. Almost half of 1,150 school-aged children tested couldn’t meet the lowest skill levels for such basic tasks as throwing, catching, kicking or hitting a ball--activities that one might expect children to perform naturally.

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But even if your DNA will never get your progeny in the NBA, you can still help your child to develop skills that contribute to being fit, says Greg Bach of the National Alliance for Youth Sports, a nonprofit organization in West Palm Beach, Fla., that works for safe and meaningful sports opportunities for children.

The problem, he says, is that unathletic parents who were never exposed to sports or fitness activities don’t know how to teach their children. And proper training in the basic skills appears to be crucial in children who are, by heredity, unathletic.

“So often parents take their child and sign them up in T-ball or hockey, and they are tossed in there without any basic understanding of the skills required,” Bach says. “The parents may not know how to teach these skills because they are unathletic.”

Indeed, Maes says, while genes appear to play a heavy role in bestowing athletic ability, the interaction between these genes and the environment--being exposed to sports or receiving training--is not well understood. Researchers often separate the two factors to examine the importance of each.

“But we’re trying to come up with more realistic models that allow for the environment and genetic factors to interact, which I think will get us a lot closer to reality,” Maes says. For example, “It’s possible that by introducing some environmental effects, that you might actually enhance the expression of certain genes that wouldn’t be expressed before. There is an interplay between environment and genetic influences.”

Some genes for fitness may be programmed to kick in later in a youth’s development--perhaps after the child has already become disheartened and given up on athletic pursuits.

“One very important aspect of this is that it’s not the case that if something is genetic that it cannot change,” Maes says. “For example, not all our genes are expressed at every age. With age, different genes might become expressed and influence fitness and other traits.”

While her study showed that heredity was the predominant factor in determining fitness in 10-year-olds, that doesn’t mean the unathletic children will always be that way, she says. The child who learns skills and works at physical fitness may find herself superbly fit and a top athlete by 17.

“Genetic factors are not stable. You can’t say: ‘It’s in the genes so I can’t do anything about it,’ ” she says.

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The trick for families who want to make fitness a priority and yet lack natural talent may be twofold, experts say. One approach is to teach your child basic fitness skills early. The second is for parents to also learn these skills and set a good example for their children by being active.

The evidence on children’s lack of readiness for youth sports led the National Alliance for Youth Sports to launch a program called Start Smart to teach parents and kids 3 through 8 basic skills.

The program, which has spread to 150 cities, teaches the basics: throwing, catching, hitting and kicking.

Parents participate too.

“Every child can learn,” says Staci Henson, who runs a Start Smart program in Visalia, Calif. “We’ve had children who have never touched a ball, and by the end of the program, they are doing as well as the other children.”

The program is especially appealing to parents who never played youth sports or who see themselves as unathletic. Lynette Uranga of Visalia worried that her children would inherit her incapacity for athletics.

“My husband is sports-orientated, but I’m not,” she says. “I worried that my daughter, in particular, would be that way. My own parents didn’t know much about sports. And I didn’t learn anything about sports in school. But I think it takes the parents to teach the child and show them the proper technique.”

While Uranga, like many parents, doesn’t expect any of her three children to be the next Michael Jordan or Steffi Graf, she does want them to be healthy. “And being fit is important for their self-esteem,” she adds.

Feeling klutzy, large or slow will have a huge impact on a child in myriad ways, says Bach of the National Alliance for Youth Sports.

“I think it’s sad that some children don’t have the opportunity to develop skills. When a child quits sports early, it affects their self-esteem, their confidence and their health. But if they have fun playing a sport, they will often continue playing it throughout life.”

Adults who run youth sports programs need to remember that many children will, initially, have a very hard time learning skills. But they can learn. And, more important, they can learn to love the feeling of being in control of their bodies, of being active and fit.

“It’s very important that sports-related activities are not only focused on those who will do well and help a team win but [also] focus on those who need to attain levels of fitness that will help them stay fit their whole lives,” Maes says.