YOU WON'T RUN THE RISK OF INJURY IF YOU RUN IN WATER WEARING A WET VEST

About 15 million Americans periodically shelve their running shoes to recover from such road-induced injuries as shin-splints, stress fractures and muscle tears and pulls. If you are among them, here's some advice from Lynn and Glenn McWaters: Go jump in a lake. Or a pool or pond or any calm body of water that's over your head. Of course, you'll want to be wearing a royal blue Wet Vest ($99.50, patent pending), a two-pound armless jacket that keeps you afloat while you move your arms and legs as if running. True, sprinting in a Wet Vest feels something like fleeing monsters in a nightmare—you don't get far. But that's O.K. You're not supposed to.

A bright, unassuming young couple—they never considered naming their product "McWet Vest"—the McWaterses are based in Birmingham. Lynn is president of Bioenergetics, Inc., which markets Wet Vests. Glenn, an ex-Marine and president of the Sports Medicine and Fitness Institute of Birmingham, designed the vest. Since Wet Vests became available in February, the McWaterses have sold several hundred and have a backlog of 150 orders. Minnesota of the NFL and the athletic department of Washington State of the Pac-10 are among those that have ordered them, and others are sure to follow. Why?

Drastic improvement among world-class and college runners who have used them has something to do with it. Spinning their wheels in water, runners can intensify training without the "neuromuscular trauma" that attends pavement pounding—shinsplints, etc. In a Wet Vest, you can "hurt yourself" without hurting yourself. Depending on how hard you work out, water offers 12 to 43 times the resistance one experiences on terra firma. Says Glenn, grinning wickedly, "Every cell of every muscle is subjected to increased workload." But safely. The chances of injury during a Wet Vest workout are almost nonexistent.

Glenn's introduction to "the healing powers of water" occurred in 1970, when as a Cobra gunship copilot in Vietnam he was hit by a .30 caliber machine-gun slug that passed through his left leg and severed the femoral vein. After a month in a Japanese hospital he returned home to Bessemer, Ala. with a Purple Heart and rehabilitated his leg by exercising in the local YMCA pool. "It healed quickly," McWaters says. "That's when I learned how valuable water therapy can be for injured athletes."

He later began a quest for the ideal vest for water-running. All were either too bulky, inhibiting good form, or too buoyant, leaving one's shoulders out of water. After splashing ideas around for several years, he designed the Wet Vest in 1980. His most notable success to date: helping sprinter Willie Smith overcome a string of injuries to make the '84 Olympic team. Coming out of a two-year retirement in '83, Smith had been nagged by a series of aches and pulls. When it appeared they might keep him out of the trials, "We put him in the pool right away," says Glenn. Smith's regimen included five sets of eight 30-second "sprints," followed by intervals of rest.

Glenn also tells of a Clemson runner who trained in water four weeks before clocking a 3:45 1,500 meters, which is the equivalent of a 4:03 mile. His personal best at that time was 4:18.

"Since the '60s it has been preached that distance runners have to put in 100-mile weeks," he says. "We're making that obsolete. With three or four water sessions per week, distance runners will be able to cut their mileage up to 50 percent."

You needn't be a varsity letterman or an Olympic aspirant to benefit from hydrotherapy. "I'd say a full half of our orders and inquiries come from sedentary people," says Glenn, "folks who say, 'I don't like to run,' or 'I can't run. This is for me.' "

Submersed to the noggin and completely relaxed, one tends to lean forward in a Wet Vest—as opposed to life preservers, which make the wearer lean backward. To start, as Glenn says, "Begin running slowly in the water. Concentrate on using the exact motion you would on the road."

First use of the Wet Vest is slightly disconcerting. You'll huff and puff, and unenlightened regulars at your pool may look at you curiously. But beat on against the current and tell them you're riding the wave of the future. Remember, you're only in up to your neck. They're all wet.