If you find a personal trainer who knows what they're doing, hold onto them. The trainers at many health clubs are poorly trained and require absolutely no credentials beyond a quick online course. A bad trainer can cause you to end up in a lot of pain.

If you're looking for a good trainer for your health club routine, look for someone with credentials from a respected institution where they were required to learn their trade before being licensed. The American College of Sports Medicine and the National Strength Conditioning Association are both good choices.

Here's a good reason to go month-by-month with a health club: even if you want to quit, they may not let you. Even if you move, you may discover that they've dinged your credit rating for not paying your bill -- or worse, are still taking money out of your bank account.