Boulder, Colo., has a high tolerance for both New Age seekers and sports obsession, and Tizer’s group has quietly operated at the fringe for two decades with an eclectic stew of spiritualism and self-actualization. But when he recently formed the Divine Madness Ultra Club, and one runner won a prestigious race last summer, Tizer began offering public workshops. By attracting publicity as a running coach and recruiting new members more actively, he unwittingly drove former members out of a self-imposed silence. NEWSWEEK interviews with more than a dozen of Tizer’s former students now portray a manipulative, alcoholic, sex-addicted despot who controls nearly every aspect of his followers’ lives in a sort of spiritual slavery. ““At some point, he got taken in by his own power,’’ says former member Terry Backner, 47. ““It became kind of a cult.''

Tizer wouldn’t comment, despite several efforts to contact him through attorneys, who said they advised him to remain silent because of a pending lawsuit filed in state court in Boulder by three former members. None of the 40 or so current members would speak out, either. The suit’s complaint lays out a long list of Tizer’s alleged practices: sleep deprivation, bullying and emotional manipulation. Tizer’s lawyers deny any illegal behavior, and attorney Gary Jackson insists that Tizer is no cult leader. ““Hundreds of people came and went over the course of nearly 20 years,’’ Jackson told NEWSWEEK. ““People were not restricted.’’ Tizer’s lawyers refused to comment about specific allegations: charges of sexual impropriety, coerced abortions and other forms of mind control.

Tizer attracted students in the ’70s and early ’80s with a promise of spiritual growth. Membership in The Community, as it was called, topped 100, but by the early ’90s, ex-students say, Tizer’s behavior became increasingly erratic. He called all-night meetings and made members listen to his sometimes incoherent ramblings. He restricted many members to less than five hours of sleep - he allowed one member precisely four hours and 24 minutes per night. His own nightly ritual often was to consume a few bottles of Sierra Nevada Pale Ale chased with several shots of Jack Daniel’s. What followed were often demeaning scenes. In an interview, ““Julie’’ (a pseudonym) recalls being awakened at 2:30 a.m. by another woman who told her Yo wanted to have sex. Julie didn’t want to, since she had to be up at daybreak to run 42 miles. But Julie, who like many ex-members has started a new life and doesn’t want to use her real name, couldn’t refuse without facing Yo’s wrath. Tizer insisted she drink a shot of whisky and a beer. She did, then wept quietly as he tried unsuccessfully to have sex with her, she recounts. She got a couple hours of sleep after Tizer passed out, then completed her ultramarathon run still a little tipsy. If she hadn’t, Julie says, Tizer wouldn’t have allowed her to eat that day.

Another woman who didn’t want to use her name says Tizer once got her pregnant, despite his claims that he possessed a psychic form of birth control - a mental ability to kill his own sperm. Tizer told her that it wasn’t time for her to have a child, and insisted she have an abortion, which she did. ““It was understood that if I had the baby, I was out,’’ she says.

Tizer expected more than just sex. Members donated hundreds of thousands of dollars to The Community over the years. Most members lived in group houses scattered around Boulder; many had outside jobs. One member paid cash for a 160-acre ranch in New Mexico that serves as the group’s retreat. A second former member said she turned over a $100,000 inheritance. When she later balked at forking over an additional $40,000, Tizer passed word that ““if I was really serious about transformation, I had to give away all my money,’’ the woman recalls. She gave the money.

Ironically, fanatic discipline produced a few topflight ultramarathoners. Steve Peterson, a current member who won last year’s Leadville 100, hopes to break the course record this weekend. Three others finished in the top 20 last year. Janet Runyan, a member of Tizer’s inner circle, was last year’s USA Track and Field women’s 100-kilometer national champion.

But the success clearly comes with a dark side. Children as young as 9 were required to take long, predawn runs. Coach Tizer’s training regimen has adult runners training at 120 or so miles a week, half again as many as other ultramarathoners. When Celia Bertoia, 42, complained to Tizer of intense pain in her shins after a 20-mile run, he told her to take three days off, then run again. So she ran. ““I was a quarter mile into my run when I heard my leg just snap,’’ Bertoia recalls. Unabashed, Tizer blamed the fractures on Bertoia’s brittleness, telling her it was a metaphor for her problems. ““He takes credit for everything and responsibility for nothing,’’ says former member Chris Beh, 34.

The worry among some former members is that Tizer will spiral further out of control. Six years ago, former member Kim Mooney sought Tizer’s advice after being treated for cervical cancer. She told him she was ready to leave the group, but Tizer said that if Mooney ““did not get back on the path, you will contract something more serious, faster spreading and less curable within three years.’’ Mooney left more than five years ago, but she worries about current members. ““He has totally gone off the wall,’’ says Mooney. ““I don’t want what happened to me to happen to someone else.’’ No matter how far they can run.