StairMaster Makers Take Legal Steps Against a Smaller Rival : Exercise: They claim infringement of patents on the hottest equipment in the fitness field. A countersuit says they stole the idea.


Call it Stair Wars.

The makers of StairMaster, the hottest hunk of exercise equipment to hit the market since Nautilus, are engaged in a sweaty legal battle with a smaller manufacturer of a rival step climber, the Aero-Step.

Each company accuses the other of patent infringement. At stake is an estimated $320-million market for the high-tech, low-impact aerobic machines billed as the best alternative to running.

Sales of step climbers have increased faster than those of any other exercise device, with sales to health clubs more than tripling in recent years, according to IRSA, a health club trade group in Boston. Prices range from about $130 for a simple home exerciser to $3,400 for a deluxe health club model.


“They’re everywhere,” said Malcolm B. Wittenberg, attorney for the inventor of the Aero-Step. “You can’t go into a gym today without seeing some kind of stair-climbing device.”

“Almost every celebrity who’s into health and fitness has one,” agreed Ralph Cissne, director of advertising for StairMaster Exercise Systems. “They want to have the latest and greatest, and this is it.”

But who really invented the step climber?

In a lawsuit filed in federal court here in November, Tri-Tech Inc. of Tulsa, Okla., doing business as StairMaster Exercise Systems, alleged that its 1987 patent on a “stair climbing exercise apparatus” was violated by Tru-Trac Therapy Products Inc., the Temecula, Calif.-based maker of Aero-Step.

Tru-Trac and inventor Evan Flavell responded with a countersuit. They allege that StairMaster stole Flavell’s idea for an “isokinetic ergonometer,” a device that increases resistance in response to an electronic stimulus. Flavell’s invention was patented in 1978, according to Wittenberg.

A hearing is scheduled before U.S. District Judge Gary Taylor on March 18.

Meanwhile, the two companies are waging a parallel legal war at the U.S. Patent Office in Washington, where Tru-Trac is arguing that StairMaster’s patent should never have been issued in the first place, Wittenberg said.

Stair climbers are upright devices that mimic the action either of climbing stairs or of marching up a descending escalator. They have swept the fitness market because they provide a fast aerobic workout and help slim the problem zone from waist to knee without the trauma that running can inflict on the ankle, knee and hip joints.

StairMaster introduced its first climber in 1983, and in 1986 began selling the StairMaster 4000, which retails for $2,195 and now dominates the health club market, said Cissne.

What makes the StairMaster unique is its so-called independent step system, Cissne said. That means that a climber must push down each pedal separately, which makes the workout more strenuous and therefore more effective.

Rival machines have dependent step mechanisms, which means that when a climber steps down on one pedal, the other one automatically moves up, like a teeter-totter, Cissne said.

The independent step mechanism “not only feels better, there’s less trauma” to joints, because the climber is fighting gravity without bouncing against the pedals, he said.

StairMaster claims that the Aero-Step infringes on its patent because it has an independent step mechanism, said StairMaster attorney Thomas F. Smegal Jr.

StairMaster’s success has attracted other competitors, including Life Step, made by Life Fitness Inc. of Irvine, and the Universal Stairclimber, made by Universal Gym Equipment Inc. in Cedar Rapids, Iowa.

Another newcomer is Tectrix Inc. of Irvine, which began marketing its $2,995 ClimbMax in 1989, said company President Mike Sweeney. Although Tectrix has two patents on its devices, with a third patent pending, its climber has an independent step mechanism and the company has received letters from StairMaster threatening legal action, Sweeney said.

The Aero-Step, which was introduced in 1989, costs $2,995, said Daniel M. LaVelle, vice president of marketing and sales for Tru-Trac.

Tru-Trac was founded 36 years ago to make physical therapy equipment, but has also moved into the larger fitness market, LaVelle said. In about 1986, it acquired Flavell’s company and became the licensee for his 1978 patent on the isokinetic ergonometer, he said.

That device, incorporated into the Aero-Step, makes it possible for an exerciser to chose between 100 different levels of resistence, fine-tuning the workout in a way other equipment cannot, LaVelle said. The Aero-Step also has larger steps that make it easier for physical therapy patients to use, he said.

Moreover, LaVelle said, “it’s unbelievably quiet.”

Whatever the outcome of the patent wars, the future for the step climbers looks bright.

Sales of home step climbers more than doubled last year, to $57 million, and are projected to hit $120 million this year, said Glenn Bischoff of the National Sporting Goods Assn. in Prospect, Ill.

There are an estimated 80,000 step climbers in the nation’s health clubs and fitness centers, and the replacement market for the more expensive units is worth about $200 million a year, said John McCarthy, executive director of IRSA.

“The biggest growth products in the health club industry right now are treadmills and stair climbers,” McCarthy said, adding that he expects to see sales jump 40% to 50% again next year.


These demographic figures were compiled from records of purchases made by consumers in 1989.


25 to 44 years old 78.6%


Female 61.5%


$35,000 and over 61.3%


College Graduate 41.7%


Northeast 24.3%

Pacific 17.4%

South Atlantic 14.4%

Does not include sales to health clubs.

Source: National Sporting Goods Assn.