Tae-Bo or Not Tae-Bo?

It's time for y'all to put some gas in your tanks," shouts Billy Blanks. He cranks up the volume on the stereo, and the Billy Blanks' World Training Center in Sherman Oaks, Calif., is flooded with the ragged sounds of Rob Base & D.J. E-Z Rock and human agony. Teeth clenched, sweat dripping, 150 men and women kick out their right feet, then bow at the waist and kick back their left feet. "Lean, guys, lean!" commands Blanks, as he demonstrates the move from a stage emblazoned with the message GOD IS GOOD. He then adopts a fighter's stance, and on cue the class punches left, right, left! Walking amid the flailing limbs, Blanks holds his palms out to the hail of fists, like a minister blessing his flock.

Tae-Bo is not for the faint of spirit, or the weak of back. It is a grueling combination of punches, kicks and squats set to the rhythms of hip-hop. Blanks first experimented with the karate-like sequences in his basement in Erie, Pa., two decades ago. He later opened a studio in California, where he has taught the routine to such famed hardbodies as Paula Abdul, Lisa Rinna and Wayne Gretzky. Last August he brought Tae-Bo to the people.

Or at the very least to your television set. Tae-Bo marketers shell out about $2 million weekly to air his 30-min. infomercial across the country. Lose weight! Kick butt! Free your spirit! All that is yours simply by buying a set of four videos for three easy payments of $19.95. And Blanks has crossed over into free TV too. He turned up on ER last month and spent a week with Oprah in the Bahamas. No wonder Tae-Bo videos have grossed some $75 million and placed in the top five of both the Billboard and

charts last week. Consider that a warm-up. Blanks, who is gearing up to release 24 new tapes, has agreed to write an exercise book for Bantam for a $1.5 million advance.

His booming enterprise, however, has been dogged by legal problems. His business partner, Paul Monea, who produced the infomercial, is facing two separate lawsuits: one by Sugar Ray Leonard, who contends that his name was used without permission in the Tae-Bo infomercial; and another by Seth Ersoff, an entertainment manager who claims he introduced Monea to Blanks and was later denied a share of the profits from Tae-Bo. Monea's lawyer declines to comment on the allegations. But his client's track record isn't reassuring. In 1997 an Ohio court ruled that Monea's company could not sell "the stimulator," an electric-grill lighter outfitted with a thumb plunger that, when pressed, was supposed to relieve pain.

Blanks, who looks like he could take on a Mac truck, distances himself from his partner's legal troubles, preferring to stick to his own pretty remarkable success story. "I was the one who wasn't going to be someone," says Blanks, 43. He was the fourth of 15 children born to a poor black family in Pennsylvania. He had bad hips, dyslexia and (can you hear the Rocky theme music yet?) was nearly kicked out of his first martial-arts class at age 11. Using a mirror to learn the moves and correct for his impairment, he remade himself. He won scores of karate titles, appeared in a string of B movies and was born again--in that order. He is a preacher in an athlete's body, and Tae-Bo is his one true gospel. "Tae-Bo is the only exercise that will give you everything you want," he says.

Maybe more than you want, according to skeptics. Some fitness experts fault the tapes for inadequate warm-up time and instruction. "He's working at a speed that's very quick," says Linda Shelton, an editor at Shape magazine. "Too quick for most people to execute a safe kick or punch." The many repetitions, often without modifications, may risk overuse injuries to the shoulder and back. "This is a program for the fitness elite," says Petra Robinson, a vice president at the American Fitness Association. "It's too intense for beginners."

Don't tell that to Marsha Boysaw, 37, an attorney who works out to Tae-Bo four times a week. Her abs jut out below a damp sports bra as she discloses that she lost 38 lbs. in her first six months of Blanks' vigorous workouts. Jackie Gradinger, 30, a veteran of the treadmill and step aerobics, proclaims Tae-Bo "the hardest workout I've ever done." She too is impressed by its effect on her waistline, but she adds, "I do it mostly for my mind." Lynne Devlin, 37, a preschool teacher who ordered the tapes in January, finds the mind-body benefits in perfect balance. "My energy is through the roof," she exclaims after the hourlong workout. "Now I can go clean the house!" And while she does, Blanks is cleaning up.