When to negotiate: You'll save the most when your gym offers the biggest promotions, usually around the new year.
As The New York Times puts it, "Gyms ... often operate a bit like airlines or car dealerships; people working out next to each other may be paying different rates depending on when they signed up and other factors. Those who sign up in slower seasons or around the New Year when the most promotions are offered, for instance, tend to pay less than those who sign up during other times of the year, according to industry sources."
How: Pamela Kufahl, editor of Club Industry magazine, recommends research as the first step. Look at the websites of the clubs in your area to narrow down your choices, and pay them a visit. While you're there, ask for a free one- or two-week pass. Once you know where you want to go, ask friends who are members what they pay, or check online message boards to find other people's rates. Also, check with your employer or guidance counselor to see about deals offered through work or school.
Then take that intel to your preferred gym. If they quote you a rate higher than what you know other people pay there or what you could pay at a similar gym, Kufahl suggests, "Say 'hey, my friend was offered this rate two months ago, can you match it?' or 'I checked out New York Sports Club and they are offering this rate, could you match it?'" She also recommends asking about promotional rates coming up and whether the staff can waive initiation fees. If the answer is still no, try asking for other perks instead, like free personal training sessions.