BIG BUM WEIGHING YOU DOWN? GET Rid of Him, the book Joyce Vedral published early last year, offers one solution. But there's another kind of big-bum problem—and Vedrals Bottoms Up!, published in December, promises to take care of it by transforming readers "from cellulite to sexy in 24 workout hours."

Buoyed by new rears resolutions, Bottoms Up! has lately bounced onto best-seller lists, hilling No. 1 in the advice/self-help category in The New York Times.

All this success leaves Vedral, a 50-year-old former English professor who has found her calling as a writer of exercise and self-help books, silting pretty. Bottoms Up!—which stresses weight work for the entire lower body—is her 15th book (others include The Fat-Burning Workout, My Parents Are Driving Me Crazy and Gut Busters) and her biggest hit. Fans of Montel Williams and Sally Jessy Raphaël have seen the enthusiastic fitness guru from Wantagh, N.Y., plugging the benefits of at-home iron-pumping.

She also espouses low-fat eating and aerobic workouts. "Bui the weights—three, five and eight pounds to start, 20 to 30 minutes a day—are the most important," says Vedral. "That's the only thing that shapes your body."

Her own body, she says, was so out of shape 20 years ago, shortly after her divorce from preacher Chuck Vedral and a year after the birth of her daughter Marthe that she overheard people speculating that she was pregnant. "I don't have good genes," she says. "My whole family is fat." A series of diet and exercise programs didn't help. Then, when she was 39, while writing freelance articles for bodybuilding magazines, Vedral went to the weights herself. Now she carries a solid 115 lbs. on her muscular 5' frame.

Vedral says she is dating several men and enjoys ballroom dancing, target shooting and mountain climbing. "I'm working on a Bottoms Up! video," she says. "I want to write novels and do a motivational TV show. I'm 50 and I've got nothing to lose. Beware a woman who's got nothing to lose."