10 Things Your Fitness Club Won't Tell You

In the meantime, there are ways to avoid January overcrowding and make it past the 90-day hump. When selecting a new gym, visit the facility during the time of day you're most likely to attend. If it's crowded, check to see whether waiting lists and time limits on machines are enforced or whether it's a free-for-all.

In swabs of medicine balls, for example, Tierno found samples of community-acquired MRSA — a strain of staph resistant to some antibiotics. "You take your chances," Tierno says. "Any time you touch a medicine ball or machine, you have to know that your hands are contaminated and should be washed."

What about those spray bottles some gyms provide for wiping down equipment? They may help, Tierno says, but he recommends additional measures, such as wearing long sleeves and pants while working out. Also, bring your own towels, since there's no guarantee that your gym's linens have been bleached or rinsed in clean water. While in the locker room, make sure you wear flip-flops, and avoid sitting nude on any exposed surface.

While effective CPR can buy time, it won't reset a heart after cardiac arrest. That's where automated external defibrillators, or AEDs, come in. Chances for revival drop as much as 10% each minute that passes without proper CPR and defibrillation. But even in states like New York that require gyms to have CPR equipment, as well as AEDs and trained personnel in clubs with over 500 members, two-thirds surveyed by the attorney general's office in 2005 weren't in compliance. Find out if your club has the right equipment and, equally important, staff trained to use it.

Jonathan Jacobson, a marketing exec with a degenerative disk disease in his lower back, sought out a trainer to design a routine appropriate for his condition. But after following a boxing regimen the trainer recommended, he was left in pain. When his doctor told Jacobson, 35, to stop, the trainer suggested Pilates — which only further aggravated the problem, ending in a slew of medical procedures. "He had certificates and tons of plaques on the wall," Jacobson says. "It's taken about a year to not be in pain every day."

Seek trainers with credentials from respected institutions like the American College of Sports Medicine or the National Strength Conditioning Association — preferably with some training in sports medicine or phys ed.

For those paying monthly, calls from collectors or a battered credit score may be the first clue membership was never terminated, says Todd Mark of the Consumer Credit Counseling Service of Greater Atlanta. Follow contract terms to the letter, providing proof of a move or a doctor's note. Create a paper trail, and alert credit agencies about the dispute.

Your best defense: Read every word of the contract. Never rely on a suave salesperson's "word" no matter what authority they profess, and don't let anyone pressure you into signing before you're ready — take the contract home and read it overnight.

Take equipment maintenance, for example. Although manufacturers must include instructions with exercise machines, nothing forces gyms to follow them, Rabinoff says. Injuries can result from poorly or improperly maintained equipment, says Cedric Bryant, chief science officer for the American Council on Exercise. Harold Leon Bostick knows that all too well. Due to a design defect in a machine he was using, a stack of weights came crashing down while the law student was doing squats at a California gym in 2001, severing his spinal cord.

Bryant recommends asking to see maintenance and cleaning logs — hallmarks of a good club. Gold's Gym, for one, says it follows manufacturers' maintenance guidance to the letter and replaces equipment every five to seven years. And avoid machines that stick or don't move smoothly.

Already a member? Jot down these specials, and ask for one of them when it comes time to renew your membership. Some gyms will honor the rate months after the posters come down, says Mark, of the Consumer Credit Counseling Service of Greater Atlanta. If you're looking into a new membership, remember that the cheapest deals will likely be those that lock you in for a long time. For example, Bally's flexible plans, including month-to-month memberships, typically cost $5 to $10 a month more than its popular long-term "Value Plan." As for trainers, you might be able to get a break if you decide to share sessions with a friend or two, says Carol Espel, Equinox's national group fitness director.

Ben Osbun tried to end 2004 on a healthy note by working out at his local YMCA on New Year's Eve. But the day quickly soured. When the Chicago real estate agent returned to his locker, he found that the padlock had been cut and his cell phone, keys and wallet were all missing. Only his jacket was left behind; the thieves showed him some mercy since it was December, Osbun says. He adds that the gym staff wasn't particularly surprised by the incident, since petty theft is common in health clubs. Osbun learned his lesson; he now brings very little with him to the gym.

If you do intend to store items in a locker while you're working out, IHRSA recommends using a padlock with a key, which is harder to pick than a combination lock. Good to know — not that it would have helped Osbun any.

In Michael Stokes's case, it was a defect in the basketball court's floor at his Kent, Wash., gym that caused ruptured tendons in his knee and shoulder. While a judge found that Stokes may not have known what he was signing, a subsequent Court of Appeals ruling upheld the waiver and dismissed the case, says Mark Davis, a lawyer at Curran Mendoza who represented Stokes.

And that's how it usually goes, since the majority of states' courts tend to side with the gyms on the matter of liability waivers, while only a handful, including those in New York and Virginia, are likely to rule against them. Occasionally, a judge will rule on behalf of plaintiffs in instances of gross negligence, but that bar is set pretty high in some states, such as Washington, Davis says.

Bottom line: Understand that you're taking your health in your own hands when you go to the gym, so you need to watch your own back — literally.