In recent years, sports medicine experts have embraced aquatic exercise as an ideal way for injured athletes to maintain cardiovascular fitness while rebuilding strength and flexibility in a low-stress environment. High-profile athletes who have taken the plunge to rehabilitate injuries are figure skater Nancy Kerrigan, quarterback Troy Aikman and track star Carl Lewis.

"Ten years ago, water exercise was pretty much for older adults," See says. "Now you'll find people of all ages and ability levels doing all kinds of workouts in the pool." Among the most popular, she says, are classes such as aquatic kickboxing and aquatic boot camp, deep-water running wearing a flotation belt, water walking and practicing Eastern arts such as tai chi and yoga in the pool.

"This means you naturally get a balanced workout in the water," she notes. For those who want an extra strengthening effect, [Pat Cook] recommends adding resistance with some of the innovative "pool toys" designed for water workouts, such as webbed gloves and aquatic dumbbells.