TV's hot new characters for preschoolers are designed to get the little couch potatoes up and moving.

PBS' "Boohbah," (search) Nickelodeon's "LazyTown" (search) and the Disney Channel's "JoJo's Circus" (search) are all examples of an industry-wide search for programming that responds to the increase in childhood obesity — for which all the time spent in front of the tube gets some blame.

Networks are eager for parents to see them as being part of the solution instead of just the problem.

There's a simpler idea — tell the kids to turn off the TV and go play — but that's not exactly good for business.

"There is a certain irony in it, creating TV shows to get kids to stop watching the TV and be more active," said Amy Jordan, an expert on children's television at the University of Pennsylvania's Annenberg Public Policy Center. "But this is a problem that has to be addressed on several fronts. We need to get parents to understand how much children watch television."

Some experts have found that children expend less energy watching television than they do while sitting quietly and reading a book, she said.

The success of such programs as "Dora the Explorer" and "Blues Clues" proved many children enjoy using television interactively, to help on-screen characters solve a problem or to follow cues in learning how to read, said David Campbell, executive producer of "JoJo's Circus."

The idea now is to apply the same techniques toward physical activity.

With songs and games, "JoJo's Circus" viewers are invited to walk, run, dance, jump, climb and move with the characters.

Nick's "LazyTown" has been the top-rated show on commercial television among preschoolers since starting in August. Its creator and star is Icelandic aerobic champion Magnus Scheving.

Eight-year-old Stephanie and her friends live in a village where they are caught between a health-conscious superhero named Sportacus (played by Scheving) and Robbie Rotten, who spends his time lying around and eating junk food.

Another new Nick show, "The Backyardigans," (search) is an animated feature about five neighbors who take musical adventures. Each show features original songs and choreographed dance steps in genres like funk, swing and reggae.

Nick has lumped its preschool programming in one block, with a get-up-and-go host named Piper O'Possumm and a new tagline: "Love to play!"

"There are shows that engage kids and shows that are very passive," said Brown Johnson, Nick's executive vice president. "Nick Jr. has always had the point of view that kids watch with an active mind."

"Boohbah" came from British producer Anne Woods, the same fanciful mind behind "Teletubbies." (search) The five odd objects that are the show's "stars" encourage young viewers to do things like the "lobster dance," or to solve puzzles. The "Boohbah" characters went on a national fitness tour this fall.

"I think PBS may be the only network that actually thinks it's a good thing when the child turns off the television and picks up a book or goes out to play," said John Wilson, the network's programming director.

Public broadcasting also has the luxury of not depending on ratings to set advertising prices. That's unlike Nickelodeon, which actually went off the air for three hours one Saturday this fall to encourage children to go play. Business realities dictate that's not going to be a regular part of the schedule.

PBS encourages producers of all its children's programming to make characters that behave the way kids should behave, and that includes being active, Wilson said.

The network is always on the lookout for other programs that encourage exercise, but it's no easy task.

Campbell and his partner, Jim Jinkins, said it was a conundrum for them when first approached by Nick executives who wanted a physically active show.

"The real key is you want to get them up and moving but you don't want them to turn their heads from the TV," Jinkins said. "You want to engage them in the story. It's a tricky thing."

Commercials for junk food are also part of the equation, Jordan said. Johnson said Nick has had extensive meetings with advertisers to try to meet objectives for more healthy living.

"I don't know if we always have to be cynical about what the networks are doing," Jordan said. "Maybe they actually do have the children's health under consideration. They also have to consider that parents are being more careful of what their children are watching."