Toddler athletes a growing trend

A growing number of American parents are putting their toddlers in sports classes.

(CNN) -- Nicholas is trying to rush the net, but the net's a little taller than he is. Tatiana has her racket in the right position, but unfortunately she's looking at her father, not the ball when it whizzes past her. And Noah might actually be able to hit the ball if he would only face forward instead of backward.

These tennis players are between two and three years old. They are part of the "downward creep" in sports which has children playing organized sports at ages when their parents were still in sandboxes.

Sylvia Singleton offers tennis lessons in suburban Washington to children as young as two for $40 a half hour, and she has lots of willing takers. In nearby Montgomery County, Maryland, three-year-olds learn golf in a sports camp. The county even offers 30 classes for infants, from music to massage. Three years ago there were none. And in Loudoun County, Virginia, soccer classes begin at age three.

Sunny Erlanger, mother of three-year-old Paige, says given the competition, starting at three is a necessity.

"I think you have an edge starting at three with all her friends starting at four and five," says Erlanger. "It seems that it's gotten so competitive in this area that you have to start them younger."

Erlanger says soccer is only Paige's second sport. Tennis is her first.

"We have her playing tennis every day now. She hits about 70 balls over the net. So maybe one day she'll be the next Venus or Serena, we're hoping."

Experts say many kids burn out on sports by the time they are 15 years old.

Many parents dream not only of future superstars, but college scholarships. Rick Oldfield of Loudoun County's Parks and Recreation Department says it's parents who are driving the downward creep.

"It's almost like as they're ready to start walking they are ready to put a bat or put a soccer ball in front of them and start going," says Oldfield. He says he gets lots of calls from parents of young athletes.

"They're calling to ask us to increase the practice days for a team. 'Instead of one day a week, why can't we have it for three days?'"

While the toddlers may be having fun, it's not easy to keep it fun as youth sports become more and more competitive. That can lead to burn-out.

Dr. Eric Small of the Sports Medicine Center for Young Athletes in Manhattan says he sees a lot of burn-out.

"The number one reason why they're quitting is that it ceases to be fun," Small says. "So why is it not fun? Because it becomes too competitive. They're not getting enough playing time. They're frustrated."

Small says another problem is the growing trend of children specializing intensively in one sport at younger and younger ages. In the decade he's been treating sports injuries he has seen a major increase in "over-use" injuries. Ten years ago 10 percent of his patients had such injuries. Now it's 75 percent.

"They develop stress fractures and tendonitis due to the fact that they're not resting their muscles and they keep over-using them," says Small. "These injuries are more serious and harder to treat than acute injuries. They can lead to chronic pain and arthritis in later life."

With alarming child obesity rates and the tendency of electronic games to turn American kids into couch potatoes, getting young children involved in physical activity is a good thing, say experts.

But two- and three-year olds can learn skills playing catch and kicking the ball with their parents in the back yard just as well as they can signing up for formal classes. The trick is to make sure it stays fun for the kids.