Even this week, with temperatures flirting with triple digits, the scene is the same as it is on most summer days at the neighborhood pool: kids frolicking in the water, splashing up a storm, getting whistled every 30 seconds by a no-nonsense teenage lifeguard.

Meanwhile, the kids' parents sit safely out of the splash zone, reclining on chaise longues, reading novels.

What a wasted opportunity in the eyes of Molli Bot.

Bot has been an aquatics exercise instructor for more than 30 of her 55 years. Most recently, her focus has been on rehabilitation, from helping injured elite athletes return to form, to allowing arthritic octogenarians to regain the freedom of movement they once enjoyed.

She has seen what the miracle of water workouts can do for the infirm and wonders why more people -- especially those who are already at the pool with their kids, in their swimsuits, just inches away from this fountain of youth -- don't take advantage.

"There's nothing most people can't do in the water," says Bot, who has run the aquatic exercise programs at the Rex Wellness Center in Cary since 1998. "It's huge," she says of aqua exercise. "It opens up the world."

She's not talking about swimming 36 laps at 5 in the morning or doing a grueling water aerobics class after work. She's talking about a fun workout in the pool with your kids, a workout you probably won't know you've gotten until you fall into bed exhausted that night.

"Parents can do all kinds of things in the water with their kids and get a good workout," says Bot, who belongs to the Aquatic Exercise Association.

"Buoyancy creates a reduced impact exercise alternative that is easy on the joints, while the water's resistance challenges the muscles," according to the Florida-based nonprofit's Web site.

Many people don't think of playing with their kids in the pool as a workout for a couple of reasons. One, it's fun and workouts aren't supposed to be fun. And two, says Bot, a critical ingredient of the land-based summer workout is missing: sweat.

Yet according to the AEA, studies show that while exercising in the water typically results in a lower heart rate than on land, oxygen consumption is comparable and the cardiovascular benefits similar.

And you can burn about the same number of calories working out in the water as you can on land. A 1992 study cited by the AEA showed the combined upper and lower body impact of a moderate water aerobics class was comparable to running 10-minute miles. Both activities, according to the study, would burn 400 to 500 calories over the course of an hour.

That's because of the resistance water offers, a feature that benefits water exercisers in another way. "That resistance offers all the benefits of hydrostatic pressure," says Bot. "It's almost like a massage. Think about all that pressure on your body."

Though a play workout in the water is good for anyone, Bot and the AEA say it's particularly beneficial for folks suffering from osteoporosis, arthritis, diabetes or menopause, as well as for people with back problems and women who are pregnant.

You may not think of the pool as an exercise spot for another reason, Bot says. For most adults it takes us back to a time of endless energy, when playing was what life was all about. A time when the embrace of cool, chlorinated water washing over your skin offered the ultimate in escape.

"It's sensuous, it's tactile," says Bot. "It takes you back to childhood."