Fitness Folly Times Five

Whether it's skipping a warm-up or fudging on form, a lot of us make the same workout mistakes.

Look around a gym and you'll see people making the same mistakes: Failing to warm up. Using improper form. Doing the same old routine. Focusing their work on one area of the body. Exercising too hard or barely breaking a sweat.

"Those are all pretty common," says trainer Patrick Hagerman, Ed.D., clinical assistant professor of athletic training at the University of Tulsa. "As much as 90 percent of people who haven't had professional instruction are making one or more of them."

Here's how to avoid five mistakes that can lead to frustration, injury or skipping workouts altogether.

"And they're off!"

For most people, the clock is ticking even before they get on a treadmill or exercise bike.

"People are in a hurry, so they skip the warm-up and jump right into whatever they are doing," Dr. Hagerman says. "That's when muscles get strained and torn." He compares muscle fiber to a stick of chewing gum: When it's warm it bends, but when it's cold it snaps.

Doing your normal activity at a low intensity for five to 15 minutes will give muscles enough elasticity. If that's the treadmill, set the pace at a brisk walk. If it's lifting weights, do a set at a third to half of your normal load.

Forgetting form

We usually work out with a goal. We want to lift a certain weight. We want to touch our toes. In going for the goal, we often ignore how we're getting there.

"The mirrors in a gym are not there because exercisers are egotistical people," says Richard T. Cotton, chief exercise physiologist for the American Council on Exercise. "They are there so you can be aware of your form."

But a mirror only helps if you know proper form. "People don't get proper instruction," says Dr. Hagerman. "They just copy someone else who is doing it wrong and it perpetuates itself."

Find a good source of information, be it a lesson with a personal trainer or a reputable book or video. Then watch what you're doing while you exercise -- and cut back on your workout if you're cutting corners on form.

Stuck in a rut

People often end up doing the same workout for months and wonder why they lose their enthusiasm.

Your pet workout may seem to keep you in shape, but a body needs variety. "Muscles can get into a routine, too," says Dr. Hagerman. "You need to challenge them in different ways or your workout becomes just another thing you do."

A program should be changed, at minimum, every three months.

Dr. Hagerman suggests you make each workout different. "You should even do the things you don't like," he says. "Those are probably the exercises your body needs the most."

Spot training

Most of us would like to reshape a part of our bodies. But you can't reduce fat in a particular area with specific exercises. "You can do crunches 24 hours a day, but you won't be able to see those abdominal muscles if you still have fat around your stomach," says Dr. Hagerman.

If you need to lose pounds, make sure you burn more calories than you take in. If you do that, you'll lose fat, and eventually, some of that fat is going to be in the areas that you are targeting.

To shed fat, build muscle. According to Mr. Cotton, research shows that a pound of muscle burns 35 to 75 calories per day as opposed to eight calories for a pound of fat.

Off the pace

Knowing how much to exercise can be tough, particularly for a beginner. You should start by discussing your fitness program with your health care provider.

One useful tool is the perceived exertion test. Mentally rank your exercise from zero (think reaching for the remote) to 10 (think winning an Olympic race). Healthy people should keep workouts at five or six. The conversation test also works. You should be able to talk with someone while exercising.

If you have a hard time gauging intensity, just wait until the next morning. "When you get up, if you have some moderate [muscular] soreness, that's good," says Mr. Cotton. "If you can't get out of bed, then that's too much."

You probably recognize some of these mistakes from experience. But at least you're not making the biggest mistake: not working out at all.