Do sweat it -- at the gym

If you overindulged during the holidays and feel like you're starting to resemble Santa more than the Spice Girls, you're not alone. Many people gain weight this time of year, and one way to drop those extra pounds is to start an exercise program.

Maureen Nelson, of Pleasant Hill, lost 40 pounds in a year, working out at a gym that had facilities in Walnut Creek near her office and in Concord and Martinez near her home.

"I improved my eating habits and went to step and kickboxing classes six to seven times a week," she said. "Boy, the people at work sure noticed! The big payoff was when the handsome sales director said I looked fantastic and a senior consultant I'd had a crush on said I looked sexy."

Of course, not everyone can make it to the gym as often as Nelson. But most people can benefit, albeit somewhat more moderately.

Luckily, fitness facilities practically outnumber gas stations in the Bay Area, and chances are there's one that's right for you. Here's a rundown of some various local offerings, plus some tips from experts on how to choose the best one.

First, evaluate your needs. Do you love to swim? Or maybe you're a lone wolf and like to lift weights and do cardio machines -- or an industrial strength extrovert who goes for group exercise. Find out which gyms offer what you're looking for, said Kathie Davis, executive director of San Diego-based IDEA Health & Fitness Association.

If you spend a lot of time at work, find a facility near your workplace; optimal is a gym near both work and home, as was the case with Nelson.

If you're going to be doing aerobics, "ask if the facility has installed a floor that was designed to reduce shock," said Davis.

Most gyms will let you check the place out for a while for free. Once you've got that free pass in your hands, have a look around and schmooze with current members in the locker room. Is the gym clean, the equipment well-maintained?

A critical question: Does the facility have adequate room for the number of members who want to work out?

If you're interested in group exercise, be forewarned that many Bay Area gyms have critical overcrowding problems. Even during slow times, for example, at some facilities members are regularly turned away from classes such as indoor cycling because too many people want to participate. January and February are traditionally the busiest times of year, so talk to established gym members and check out classes at the time you'd like to attend before signing up.

Also, work with a facility that has an established reputation, read your contract and remember that it's a binding agreement, Davis said. Also, it's a good sign if you're given a health screening form to fill out, asked questions about your health and whether you're under a doctor's care before you sign up, Davis said.

If you're a woman who is beginning an exercise program for the first time, need to lose more than 20 pounds or just don't like the idea of a coed gym, the nearly ubiquitous Curves might be a good choice.

Curves has more than 50 East Bay facilities, according to the Curves Web site, with clubs in Fremont, Oakland, Walnut Creek and Antioch, to name just a few. Actually, as it happens, there are about 1.5 Curves for every two McDonald's in the United States (and use of the one may create a need for the other).

The sign-up fee is around $75 (unless you catch a special) and dues around $40 a month.

Curves makes it simple for its members, providing a group of weightlifting machines to be worked in a circuit, with a tape that tells the exerciser when to move to the next machine.

For those who want a more varied set of offerings, Pleasanton-based 24 Hour Fitness could be the ticket. The company, founded by Mark Mastrov in San Leandro in 1983, now has about 50 facilities in the East Bay and a total of 385 clubs in 16 states. The East Bay clubs have machines such as treadmills for cardiovascular workouts, free weights, weightlifting machines and locker rooms with showers. Most also offer group aerobics classes such as kickboxing and indoor cycling, and some have amenities including pools and basketball courts.

Prices vary, but at the end of December, for one example, an all-clubs membership with the Walnut Creek facility as home club had a sign-up fee of around $250, including last month's dues, and monthly fee around $50 for an individual. Another well-known club is the YMCA, which has facilities in cities including Berkeley, Albany, Richmond, Oakland, Livermore, Pleasanton, Pleasant Hill, Hayward and Fremont.

Offerings vary from club to club, but the YMCA near the Hilltop Mall, for example, has classes including merengue, country line dance and kickboxing, as well as a six-lane pool, weights and basketball, volleyball and racquetball courts.

Sign-up fees and dues are different from club to club. As one example, it costs $50 for individuals to join the Hilltop Y, with $62 monthly dues; family and other rates vary.

There are a number of other gyms in the East Bay, including Club One, which is in Oakland's City Center next to the 12th Street BART station. If you sign up -- individuals pay $95 a month, and sign-up fees vary up to $250 -- you can also work out at any of the club's many facilities in San Francisco.

An endless supply of towels plus a Jacuzzi and two saunas in the locker rooms, racquetball and squash courts, an indoor track and a pool distinguish this relatively upscale club. There's also a full schedule of aerobics classes, weightlifting equipment and cardio machines.

And, if your resolve should begin to falter, just remember Maureen Nelson. "The real key is the intensive workouts you can only get at a gym class," she said.