The treadmill in Linda and Robert Gretton's Lake Jeannette home was not getting any exercise.
Linda Gretton's bad knees and a shared lack of enthusiasm led the couple to find a different type of equipment to help them stay in shape. They chose a counter-current swimming and exercise machine, a long name for a swimming pool no bigger than a Chevrolet Suburban.
In the Gretton's Endless Pool, one of the top-selling brands, an underwater hydraulic motor produces a continuous current so they can swim in place, much like runners do on a treadmill. The counter-current is produced by a 16-inch propeller inside a protective, stainless-steel cage. "It's like if you were going to the ocean and ended up swimming against a wave that never ended," says Linda Gretton, 47. "Essentially, you can swim for miles and still be in the same 9-by-15ft swimming pool."
The swimming pool can be installed indoors or outdoors. A smaller dose of chlorine (1 part per million, compared with as much as 3 parts per million in a regular swimming pool) permits indoor installation without owners' homes beginning to smell like a gym. But the Grettons installed the pool in their deck so they could swim against the backdrop of Lake Jeannette.
The Grettons sprang for an Endless Pool model that is bigger and deeper than the standard model. But Linda Gretton says they basically bought two items for one price because the swimming pool doubles as a hot tub. After an intense calorie-burning swim, she and her husband often sit on the pool's built-in seats and turn on the Jacuzzi jets to relax.
She and her husband often use the pool together: One person swims against the smooth counter-current while the other stands at the opposite end, in the 5-foot-deep water, to do aerobic exercises. And the adjustable counter-current allows them to swim at an easy pace for a calm sidestroke or to rip through the water like Olympic contenders.
The biggest selling point, however, is the luxury of having all of that at their doorstep.
"It always seems to me such a huge effort to get everything together-your bathing suit, your towel, your drink, get in the car, go somewhere. It's always such a huge production," Linda Gretton says. "When you have something like this in your back yard, it's convenient, so you use it several times a day."
A swimming pool of this type uses 2,500 to 3,800 gallons instead of the typical 20,000 to 30,000 gallons that a regular pool uses-a fact of particular concern to the Grettons given Greensboro's drought and the cost of heating a traditional pool.
Chris Wackman, senior vice president of Endless Pools, says exercise pools have become more popular in recent years. When the company was founded in 1988, it sold 30 pools. By the end of 2010, the company had sold over 20,000.
"There's realization that water exercise is the best aerobic exercise you can get," Wackman says. "It's low-impact, so it doesn't affect your joints or tendons. It's aerobic and anaerobic, and it's fun to do."