Buff. How we worship the word and yearn for all it conjures up. Hard bodies, washboard abs, taut thighs, tight buns. Buff is beautiful. HIV status is irrelevant when it comes to the desire for a more built and beautiful you. But people with compromised immune systems should look before they leap onto that Universal machine or Stairmaster. We all want a body to die for, but take care you don’t kill yourself trying to get one.

No one disputes that exercise can make us look and feel better. But while a regular regimen is good for what ails you, the gym itself may be hazardous to your health. “A gym’s warm, moist environment provides the perfect setting for bacterial overgrowth--like a petri dish,” says Dr. Beverly Shapiro, a Philadelphia physician and acupuncturist. “You have to take special precautions against the germs that thrive on people with immune-system dysfunction.”

The Listerine commercial in which the germs in your mouth look like some X-Files-style underwater world replicates your health club under a microscope: Very creepy. Fungi and bacteria abound, an annoying byproduct of sports enthusiasm. Tiles, mats, equipment, even doorknobs are literally crawling with everything from fecal coliform (just what it sounds like) to Staphylococcus to Candida. The weights are coated with sweat--and a high concentration of bacteria. Herpes can live outside the body for close to half an hour. And not everything dripping from your workout partner is a buff-building bodily fluid; colds and flu rarely keep compulsive gym bunnies in bed.

A 33-year-old accountant with HIV, Stephen Wicek works out three times a week at his Philadelphia gym. Scabies and a sever bout of dermatitis came with the territory. “I gave my love scabies before I knew I had it, and he’s a lot sicker than I am,” he said. “It took several months for us both to get over it.” And several more for Wicek’s lover to stop being upset with him for not exercising more care. “Terry got all the bad effects of the gym and none of the benefits.”

Megan Kelly, a 36-year-old HIV positive teacher, found similar problems working out at a women’s health club in Oakland, California. “First I got athlete’s foot, then a nail fungus, then a rash that turned out to be a staph infection. My doctor said to use cotton gloves when I lifted weights and to stay away from the steam room.” Kelly adds, “Of course, my lover warned me away from the steam room too, but for entirely different reasons!”

The steam room, sauna or Jacuzzi--health-club staples--can be particularly dangerous for PWAs. They breed bacteria and promote dehydration. But drinking from the water fountain can make matters worse: Tap water may harbor Cryptosporidium and Giardia. And tanning beds, another common gym feature, pose even more threats. Their intense ultraviolet rays can increase the risk of skin cancers and also cause drug interactions, especially with certain antibiotics and antivirals.

Before trading in your gym membership, try taking precautions. You may want to avoid altogether the obvious trouble spots, such as the steam room and tanning beds. Stay out of the shower if you can. Bring your own towels (always use bleach and hot water when you wash them) and bottled water. Never lather up with the gym’s bar soap, because bacteria breed on its hot, wet surface; instead get a bottle of antibacterial soap. Take a box of antibacterial wipes with you to your workout, and clean any surface before touching; or else, wipe your hands or other exposed skin that comes in contact with equipment after use--or wash later with soap. Wear gloves to lift weights (calluses begin as blisters that break the skin), sandals in the shower and place more than a gym buddy between your butt and the bench in the steam room.

Protecting yourself in the gym is basic stuff. Follow the rules you learned as a kid: Wash your hands after you touch anything anyone else has touched, and keep them away from your mouth, eyes, nose and ears. Taking these precautions most of the time is better than flaunting them entirely. If you build those precautions into your workout, you’ll leave the gym more buff--and leave the bacteria behind.