My exercise of choice is following a fitness DVD in my living room. It's private, convenient, and I know just how long it's going to take. I also know that my instructor is one I'm going to like ... because she never changes. But if you're taking fitness classes at a gym, you may not always know who your instructor is going to be. To help you sort out the fit hits from fit flops, Divine Caroline shares eight traits of a bad aerobics instructor:

• Forgetful Freddy. An occasional lapse in memory is just human but if your instructor is consistently forgetting the routine or what you did last week, odds are his mind is on something else.
• Lopsided Lola. If your trainer doesn't work both sides of your body equally, it's setting you up for possible injury and/or uneven muscle development -- especially if it happens week after week.
• Offbeat Olga. If your class is set to music, the rhythm should help motivate you. If your instructor can't keep a beat, it's a sure way to throw off the whole class.
  

Check out the full article on Divine Caroline for more signs that your fitness leader isn't the best.