The 5 Most Common Exercise Mistakes

Wayne Westcott, PhD, CSCS

More people start an exercise program in January than at any other time of the year. Within weeks or months, most of them have called it quits -- often because of injury. Unfortunately, many people exercise in a way that almost guarantees injuries or even chronic pain. But this common problem can be avoided.
How much exercise do you need? Opinions differ, but I recommend following the American College of Sports Medicine's guidelines -- 20 minutes of aerobic exercise three days a week... and two 20-minute weight-lifting sessions a week. This level of exercise -- along with ordinary activities, such as going for occasional walks and working in the yard -- is sufficient for fitness as well as disease prevention.
Avoid these exercise mistakes...

Mistake 1
Stretching before workouts. At one time, trainers advised everyone to stretch before exercise. It doesn't help -- and actually increases the risk for injury.
Tendons have a limited blood supply. It takes them longer to warm up than muscles. Performing stretches before a workout -- when tendons are cold -- increases the risk for microtears in the connective tissue in or around the tendon. These tears are painful and slow to heal.
Recommended: Stretch after -- not before -- vigorous activities. Warm up by performing the exercise at a slower pace and reduced resistance for three to six minutes. For example, if you plan to bike for 35 minutes, begin by riding at a slow, comfortable pace for three to six minutes.
Mistake 2
Using a barbell (a bar with an adjustable weighted disk attached to each end and held with two hands). Experienced weight lifters can safely use barbells, but a dumbbell (a short bar with weight at each end and held in each hand) is better for injury prevention. That's because the wrists are less likely to move into a fully supinated (palms facing up) or pronated (palms facing down) position, that may strain your elbows. Just about every exercise that you perform with a barbell can be done with dumbbells.
Recommended: If you're using a barbell, keep your hands in your peripheral vision. If they're so far apart that you can't see them, the wrist will be cocked at an angle and more vulnerable to strain.
Mistake 3
Performing repetitions too quickly. People who use weight machines or lift free weights tend to go too fast -- either to minimize time spent in the gym, or because accelerating the pace generates momentum and makes it easier to lift heavy loads. Fast lifting greatly increases stress on the joints, especially when people neglect proper form.
Recommended: A six-second repetition speed. When lifting weights, take about two seconds to raise the weight, then lower it to a count of four. This pace is slow enough to maintain good form throughout the movement, and fast enough to complete about 10 repetitions in one minute -- the recommended number of repetitions for most workouts.
Mistake 4
Lifting too much weight. This is among the most common causes of joint, muscle and tendon injuries.
Recommended: Warm up by lifting lighter-than-usual weights. For example, if you are going to do curls with 15-pound dumbbells, begin with eight to 12 repetitions with five-pound dumbbells. After warming up, lift no more than 70% to 80% of your one-repetition maximum. That's the heaviest weight you can lift one time.
Example: If the most you can lift at one time with dumbbell bench presses is 20 pounds in each hand, use 75% of that -- about 15-pound weights. You'll know you're in the right range if you can complete eight to 12 repetitions. If you can't complete eight repetitions, the weight is too heavy... if you can easily complete 12 or more, the weight is too light.
Mistake 5
Neglecting to cool down. The cool-down period is even more important than the warmup period -- not just for injury prevention, but also to protect the heart.
The elevation in heart rate that occurs during exercise continues for several minutes after you stop. A larger-than-usual volume of blood is being pumped from the heart throughout the body. Without continued muscle activity to help pump it back into circulation, the blood tends to pool in the legs and feet. The heart has to work harder to restore normal circulation, which can trigger high blood pressure.
Recommended: After finishing any exercise or vigorous activity, keep moving for a few minutes at a slower rate -- by walking in place or biking at a reduced resistance or slower pace, for example.

Bonus: Activity during cool-down helps flush lactic acid from the muscles. This metabolic byproduct increases during exercise and can result in muscle discomfort.
Since muscles and tendons have the best blood flow and elasticity during cool-down, it is a good time to do a basic gentle stretch that targets many of the body's muscles.
What to do: Sit on the floor with your legs extended. Bend your right knee and place your right foot just below your left knee. Bending at the waist, reach forward with your arms as far as you comfortably can toward your left ankle or foot. Hold for 20 seconds. Repeat with opposite leg. The full cool-down should last about four to eight minutes.