Do manners really count in a place where everyone sweats and grunts? You bet they do. Hog the adductor (the plate-loaded version of TV's "thigh master") at my gym and you will feel a lynch mob building around you. The average health club or gym has an unwritten code of conduct as rigid as any British tearoom. So before you commit a serious faux pas, master these simple do's and don'ts.

The number one gym commandment: Thou shalt work in. If you're doing three sets on the leg press and someone else is waiting to use it, don't say "I've just got two more sets to go" and hope that pacifies. The person stuck waiting not only has to wait while you exercise, she has to wait while you rest between sets. It's annoying and time-consuming. Instead, offer to "work in" with her. After you've completed your first set, get off the machine and let her complete her first set. When she's done, she gets off and you do your second.

Use a towel. Someone is going to use the bench or machine after you get off it. Don't leave her a sweaty souvenir. Similarly, clean up after yourself if you've left a pool on the treadmill or bike. Many gyms have paper towels and disinfectant sprays on the workout floor. Use them!

Don't personalize the equipment. If you've loaded up a barbell with weight plates, don't leave them there for the next person to contend with. And if you've left the seat jacked up or adjusted the handles to accommodate sub- or superhuman proportions, reset them for easier access.