Ten Common Mistakes to Avoid at the Gym to Stay Injury-free

Worn out shoes.
Athletic shoes need to be replaced every three to six months - even indoor gym shoes may still look clean and new after heavy use. As soon as the support to ankles and arches breaks down, get a new pair.

Incorrect bench presses.
Doing too many repetitions, too many sets, with too much weight is a set-up for rotator cuff injuries, a painful shoulder condition.

Doing "lat pulls" behind the head.
This exercise, pulling down a bar to strengthen the latissimus dorsi muscles, can be a problem for people with tendon problems in the shoulders. I recommend that it is pulled toward the sternum in front of the body.

Too many risers in step aerobics.
Novices in step classes will frequently pile on the risers to look good in class, risking unnecessary muscle soreness the next day or heaven forbid, a knee injury or a stress fracture.

Overdoing stair machines.
The kings and queens of the stairmaster who tread on the machine for hours at a stretch, leaning too far forward, overworking their quadriceps, may be in trouble. To avoid injury, balance the stair machine's uphill effect by running downhill, or doing leg presses.

Excessive impact.
Whether your exercise is aerobics or running, pounding the floor too hard can lead to shin splints or plantar fascitis. Resting, cross-training and wearing proper shoes with orthotic inserts can help.

Lifting weights without a spotter.
A spotter is someone who can not only alert you to poor technique (such as locking your legs or holding your breath), but can also help you out of trouble by reminding you of your limits.

Failure to warm up and stretch properly.
Because of time factors, people probably don't do a thorough warm-up where they break a sweat and warm their tissues. Always warm up before you stretch, this makes tissues far less likely to be injured. When stretching, make it a relaxed, sustained movement, not a bouncing stretch.

Wrong settings on weight machines.
Make certain that the seat height and other settings are appropriate for you. Too high or too low a seat places abnormal stress on your joints. Many machines are designed for someone 5'9" tall. Have a trainer help you find a setting right for you.

Unqualified staff.
Check your trainer's resume. Many groups offer certification or training, including the American College of Sports Medicine (ACSM), the American Council on Exercise (ACE), and National Strength and Conditioning Association (NSCA).