The workouts have been intense: About an hour, three times a week, the trainer steadily increasing the weight until muscles grow tougher and tighter and bulge like smooth, large rocks wrapped in satin.

And the trainees? They'll gladly pump the iron, as it were, no hint of complaint, motivated only by some words of praise -- and a few fingers scratching them on their head, ooh, right there, yeah, right behind the ears.

This is the training regimen of Zena, Blitz and Ringo. The three beefy American bulldogs from Owings Mills soon will compete with the strongest dogs in the country in the 1999 National Champion Pull-Offs.

Such competitions -- which resemble tractor pulls with dogs as the tractors -- have been growing in popularity, especially east of the Mississippi. The largest organization to sponsor the pull-offs, the International Weight Pull Association, reports that in the past five years, membership has grown from three pullers in the East to more than 100.

And the country's top dog could be Maryland's own pull princess, Zena, the pug-nosed favorite to win the championship, to be held in Pennsylvania's Pocono Mountains May 1 and 2.

Weighing in at a highly sculpted 94 pounds, she has set a record with a single pull of more than 3,900 pounds -- more than 40 times her body weight.

"Look at her little butt," says Nellie Johnson, who owns and trains Zena with her husband, Charlie Johnson, at their Deer Park home. "See how muscular it is?"

Yes, Zena has a muscular butt. And muscular shoulders. And muscular legs, front and back. The knee-high bitch is built like a Marine with a wet nose, eager to do its duty, which in this case means winning a ribbon,some dog food and perhaps a little pocket change for her owners.

American bulldogs, a relative to the much feared but not as strong pit bull terrier, have become a growing breed in the United States, and the weight pull association holds about 100 contests each year across the country.

Some 180 dogs, including the three from Owings Mills, will compete in the championship in six weight classes.

"It gets the adrenalin flowing like you wouldn't believe," Charlie Johnson says. "We do it because the dogs like it, but we like it, too."

The rules are simple enough: A dog is put in a harness, which is hitched to either a sled or a wheeled cart. (The sleds are used on softer dirt or snow; the carts are used on harder surfaces.) The sleds are laden with thousands of pounds of bricks or weighted jugs.

The owners of the dogs stand in front of them and urge them to pull. The dogs have one minute to pull the sleds 16 feet.

"I think the popularity is this bond it forms between the dog and its owner," says Dixie Smith of Montana, the weight puller association's president. "The fact that a dog will pull all that weight to you, for you, creates something special between the dog and owner."

The Johnsons have spent the past three or four years raising their dogs and training them to pull ever more weight. Charlie Johnson breeds them, relegating the weakest to a life without pups but using the strongest dogs to produce ever stronger dogs.

The American Bulldog Association claims the first famous American bulldog was Petey from the old "Our Gang" television show -- though Petey may in fact have been an American Staffordshire terrier. More recently, the dog Chance has helped popularize the breed with his performances in the film "Homeward Bound" and its sequels.

But bulldogs in their pure form have been around since as early as the 17th century. They were used in colonial America in contests with bulls, bears and buffaloes, where the dogs were expected to bait the larger animals toward them. Particularly in the Southeast, they were used to protect property and catch large animals like cattle and hogs.

So now they have to pull a lot of weight, which the Maryland Society for the Prevention of Cruelty to Animals says is fine under certain considerations.

"I would say that if they're training the dogs, slowly adding weight to their burden like you would training humans, that would be perfectly acceptable," said Debbie Thomas of Baltimore, the society's state president. "If they were beating the dog and forcing them to go forward, we'd have a problem with that, certainly."

Charlie Johnson says the animals are always properly trained. And rules of the pull make it illegal to touch the dogs or to coax them with treats. They are to be encouraged only with verbal commands.

"Some people think it's mean to the dogs," says Charlie Johnson. "It's not. It makes the dogs look good and it makes them healthy."

Earlier this week, one of his dogs, Ringo, looked neither good nor healthy. The dog may be strong but he apparently is not a great thinker. He was down, unable to walk, after he had eaten a pile of wood chips. The solution: some antibiotics from the vet and a couple of tablespoons of Pepto-Bismol.

"This breed can come back from anything," says Nellie Johnson. "But I don't think he learned his lesson."

While Ringo took a few days off from training to settle his stomach, Zena and Blitz continued their training.

Charlie Johnson hooked them up to the wheeled sled, tossed some cinder blocks on it and urged them to pull. When they did, they resembled Max, the dog from the tale "The Grinch Who Stole Christmas," as it tried to pull the sled weighed down with the gifts snatched from Who-ville: Front legs first flailed but then dug in, and with the powerful push of hind legs, the dog and cart moved forward.

All the while, Nellie Johnson stood behind the weight. In case the dog couldn't move the sled, she was ready to push it forward. "You never want them to think they failed," she explained. "You don't want them to feel bad, like they disappointed you."

The Johnsons are looking for a dog food company to sponsor them and their dogs for their competitions. Traveling to events gets expensive (though host owners help cut costs by inviting visiting owners to stay at their homes). And there is not much money in winning, let alone losing. Even a champion dog pulls in only about $50 per competition for its owner.

"What you win is recognition," Charlie Johnson says. "You prove your dogs aren't just for show, that they're good, strong work dogs even if they aren't working."

Pub Date: 4/02/99