Gyms/Exercise Clubs

24-hour Fitness

303 Second St. (at Folsom), 543-7808

350 Bay (at Powell), 395-9595

1645 Bryant (at 16th St.), 437-4188

3741 Buchanan (at Bay), 563-3535

100 California (at Davis), 434-5080

2145 Market (at Church), 864-0822

1850 Ocean (at Ashton), 334-1400

1200 Van Ness (at Post), 776-2200

www.24hourfitness.com

Sure, it's a chain, but 24-hour Fitness is still a convenient and competent alternative to the City's pricier offerings. Beware, though: Not all locations are open 24 hours a day.

Bay Club

555 California (at Kearny), 362-7800, www.bayclubbofa.com

150 Greenwich (at Sansome), 433-2200, www.sfbayclub.com

Membership to the Bay Club has its privileges, including rare amenities like childcare and shuttle service to the Financial District. While the group exercise schedule is somewhat limited, its facilities for circuit training, squash, tennis, basketball, and Pilates are not.

Bodytonic

1300 Sutter (at Van Ness), 440-1800, www.bodytonicSF.com

A soothing, almost meditative atmosphere pervades Bodytonic, which caters equally to beginners and experienced athletes. The club's philosophy of strengthening both body and soul is reflected in the training and coursework (which range from targeted offerings like "Butt and Gut" and Ashtanga yoga to culturally educational classes like "Bhangra Dance").

Boot Camp San Francisco

1052 Jackson (mailing address), 921-8537, www.bootcampsf.com

You might not be rushing to join the Army, but those who want the physical fitness benefits of being in the service may brave these intensive cross-training sessions. We believe folks when they describe their program simply as "work."

Club One

350 Third St. (at Folsom), 512-1010,

950 California (at Mason), 834-1010

2 Embarcadero Center (at Davis), 788-1010

1455 Fillmore (at O'Farrell), 749-1010

450 Golden Gate (at Larkin), 876-1010

535 Mason (at Post), 337-1010

1755 O'Farrell (at Fillmore), 749-1010

1 Sansome (at Sutter), 399-1010

www.clubone.com

Another (albeit smaller) chain, Club One offers an extensive array of services, from physical therapy and nutrition counseling to childcare and off-site camp opportunities. Resources vary from location to location, but the company is a good choice for those seeking a variety of exercise choices, whether circuit training, aquatics, or team sports.

Crunch

61 New Montgomery (at Mission), 543-1110

1000 Van Ness (at O'Farrell), 931-1100, www.crunch.com

This national chain is known for the clean, modern design of its facilities and for its friendliness toward all skill levels. But only the bold and beautiful will brave the Van Ness location's "peek-a-boo showers," where one's silhouette is lit up and on display above the club's main staircase.

Curves

555 Buckingham Way (at Stonestown Shopping Center), 681-2145

1701 Church (at 29th St.)

2300 Clement (at 24th Ave.), 387-9000

4328 Geary (at Seventh Ave.), 386-4700

2255 Judah (at 28th Ave.), 759-8900

1874 Market (at Laguna), 431-4693

1301 Polk (at Bush), 441-1444

608 Portola (at Woodside), 759-9103

638 Stanyan (at Page), 221-6932

2453 Taraval (at 34th Ave.), 664-3200

2529 Van Ness (at Union), 771-0445

www.curvesinternational.com

This national franchise of fitness centers for women of all sizes and abilities has grown in popularity in recent years because of its demanding 30-minute workout system, which includes exercises on water-based hydraulic machines that provide double-positive push-and-pull resistance for rewarding results in less overall time.

Gold's

1001 Brannan (at Division), 552-4653

2301 Market (at Noe), 626-4488

www.goldsgym.com

With almost 600 locations in several countries, the big poppa of gym franchising boasts more locations than any other chain. Over the years the company has done its best to try to broaden its muscly, iron-pumping image with a surprisingly large offering of classes, from "Dance Hip-Hop" and "Brazilian" to yoga and Pilates sessions.

Golden Gate Fitness

1247 and 1248 Ninth Ave. (at Lincoln), 564-4343 (gym), 682-8911 (studio)

3119 Vicente (at 42nd Ave.), 753-5177

www.goldengatefitness.com

The best facilities in the Sunset and Richmond areas are about to unveil a Health Sciences Program with assistance from physical therapists and physiologists. This brand-new initiative will add a strong component to these centers, which offer more than 60 classes per week with consumer-friendly names like "Love Your Ass."

Gorilla Sports

2324 Chestnut (at Scott), 292-8470

2330 Polk (at Union), 292-5444

www.gorillasports.com

Gorilla Sports, which turns 10 this year, is home of the Kwando workout, a proprietary hybrid of tae kwon do and aerobics, not to be confused with tae bo. Other main course offerings include yoga, Pilates, boxing, kickboxing, and boot camp. The Polk Street location, located in the renovated Alhambra Theatre, screens films while you work out.

Pacific Heights Health Cub

2356 Pine (at Fillmore), 563-6694, www.ph2c.com

Though it's of small use in this winter moment, Pacific Heights Health Club is the only club in the city that can boast of a retractable sky-roof. PHHC keeps its membership small and exclusive so it can offer a no-wait situation on the machines and personal attention in group classes.

Pinnacle

1 Post (at Montgomery), 781-4600

345 Spear (at Folsom), 495-1939, www.pinnaclefitness.com

Part of the mighty Bally's chain, Pinnacle is the place to go when you don't want the hard-ass strategy of fat-blasting/rapid weight loss and prefer a longer-term approach. The large class schedule in this well-rounded facility includes aqua courses, dance classes, and athletic training. Chiropractic evaluations are available.

World Gym

260 De Haro (at 16th St.), 703-9650, www.worldgym.com

Yet another large chain, World Gym offers little luxuries like a juice bar and tanning salon. The classes include spinning, jujitsu, boot camp, several yoga offerings, and the popular "Brazilian Butt Lift." Open till midnight on weekdays.