HIVers don’t need to be Greg Louganis to burn calories—and stroke immune systems—by making a splash. “Swimming is great exercise, toning the body, providing cardiovascular conditioning and normalizing blood-fat levels,” says HIV positive personal trainer Bob Weinhold. Whether in a city pool, a lake  or at the  beach, water workouts also work on arthritis and other bone and joint problems—though not osteoporosis, because swimming isn’t weight-bearing exercise. “An hour of [vigorous] swimming roughly matches the value of running six miles in an hour,” Weinhold says . Even if you just want to float, frolic or flipper around, swimming is one of the most relaxing exercises available. “If your T cells are low, make sure the water quality is safe,” Weinhold warns.

Check your local Y for lessons or laps.