By Julie Greenwalt
Updated April 22, 1985 12:00 PM

Basketball star Kareem Abdul-Jabbar tripped the first time he used it. Ralph Sampson of the Houston Rockets says it hit him on the head, but despite such awkward beginnings, both men have become enthusiastic about the newest fascination in the fitness business, the Heavyrope.

Make no mistake, this is no jump rope for the kiddie set. Priced at about $30, the Heavyrope is exactly that—eight feet of flexible synthetic-rubber tubing filled with a silica mixture that comes in weights of from two to six pounds. Beginners might view it as an oversized toy but, says Abdul-Jabbar, “It fools you—it’s a real workout.”

Mike Mattox, a former exercise and sports equipment salesman, came up with the idea in 1968 at Iowa’s Grace-land College while training for the decathlon trials for the Mexico City Olympics. Mattox had finished his day’s workout when, still unsatisfied with his condition, he spotted a section of chainlink fence and began to drag it behind him as he ran around the track. His daily workouts with the fence quickly improved Mattox’s stamina and helped him shed 15 pounds. A snapped hamstring kept him out of the Olympics, but the Heavyrope is putting him in the money today. During the past year, 100,000 Heavyropes have been sold, many to professional sports teams (Detroit Lions, New York Yankees), colleges (Boston University, Michigan State) and high school athletes. Abdul-Jabbar and Sampson, along with seven other pros, have even invested in marketing the rope. “I’m not surprised it’s taking off,” says Mattox, 41, who with his wife, Marilyn, runs their Bodyflex corporation in Grand Rapids. “It’s quick, safe and cheap. You get benefits of various exercises in a single movement.”

Independent testing results support Mattox’s claims that Heavyrope increases upper body strength and lowers heart rate and blood pressure. “It may not take the place of jogging or swimming,” says Dr. Jill Upton, director of exercise physiology at Dallas’ Institute for Aerobics Research, “but for people who don’t like to swim or jog or are confined to their homes, I would say try it.” Mattox, for one, hasn’t got the time to work out regularly; his business, at least, keeps him hopping.