Read the contract carefully too before you sign anything.
Whether it's the equipment, working out with other people, or the exercise classes that motivate you, you've got a lot of choices. The key is finding the right one for you.
Consumer Reports' national research center just surveyed some 10,000 online readers to find out which facilities are worth the money.
The respondents, who used a gym within the past six months, were asked about everything from classes to cleanliness to cost.
Bally Total Fitness, the chain with the lowest monthly fee, had among the lowest scores overall.
"They were especially low when it came to cleanliness, locker rooms, and overcrowding," said Rosalind Tordesillas, Consumer Reports.
Much better was Curves Fitness Centers for Women, though it only rated average in the survey.
"Their customers cited limited workout options and subpar locker rooms. But women did like that the facilities were cleaner than most, with less crowding and shorter wait times," said Rosalind.
In fact, most fitness chains in this report had lower scores than facilities at community centers, schools, and YMCA's.
So which clubs tipped the scales?
Independent studios that teach dance, yoga, and Pilates got top scores for classes, cleanliness, and staff. You can expect to pay around $54 a month.
But you may need to look no further than your office for a good place to get in shape. Work gyms were among the top-rated workout facilities.
Consumer Reports had secret shoppers visit seven big chains.
Each offered free passes anywhere from one day to one week. And special offers were common.
But remember, commercial gyms run plenty of promotions, so don't buckle under pressure to sign up for a great deal that's about to expire.