1. Focusing on demonstrating, rather than developing, strength. When you engage in a strength-training program, your primary goal should be to build strength, not show other people how much you can lift. More often than not, such a misplaced focal point will compromise your training efforts by its natural tendency to lessen your adherence to proper exercise technique.

2. Not strengthening what you think you're strengthening. Specific exercises develop specific muscles. When designing your strength-training program, it is important that you select the exercises that will enable you to achieve your particular training goals.

3. Not controlling the speed of the exercises. When performing strength exercises, you should raise and lower the weight under control; otherwise you're "throwing" the weight, as opposed to lifting it. As such, you should avoid all ballistic movements (e.g., dropping, jerking, and bouncing) while lifting.

4. Not exercising through a full range of motion. To ensure that your musculature retains its natural elasticity and is developed to its fullest, you must perform every exercise in your strength training regimen through its full range of motion. Otherwise, your muscles will tighten up, resulting in a condition commonly referred to as being "muscle bound."

5. Not exercising opposing muscles. Your body has muscles that oppose each other (e.g., your quadriceps muscles are "opposed" by your hamstring muscles). These pairs of muscles have a proportionate strength relationship that must be maintained in relative balance. If one becomes too strong for the other, you risk injury to the weaker muscle.

6. Holding your breath while exercising. Some individuals occasionally hold their breath while lifting to "gut out" an extra repetition. Such a practice will lead to a substantial rise in pressure in the chest that may result in either dizziness or (in extreme instances) unconsciousness. The basic rule of thumb is that you should never hold your breath while strength training. If you really want to synchronize your breathing with the exercise, inhale whenever the resistance is lowered or pulled toward your body and exhale when the resistance is moving away from your body.

7. Not exercising at the right level of intensity. A muscle becomes stronger when a demand is placed on it. If you place less demand than your muscles can handle, you'll get less improvement than you are capable of achieving. On the other hand, too much demand will either expose you to an undue risk of injury or make the exercise too difficult to perform properly.

8. Not giving your muscles an appropriate amount of time between workouts to recover from the demands placed upon them. When you stress a muscle beyond what it can normally handle, some rest is needed for the muscle tissues, tendons, and ligaments to recover. If the recovery time is too brief, your muscle may be unable to make physiologic adaptations needed before being stressed again. Conversely, if you take too much time between workouts, your muscles will gradually return to their untrained level.

9. Trying to do too much too soon. Your strength-training program should be progressive in nature. As such, you should gradually increase the stress you place on your muscles as they are able to meet the imposed demand. Keep in mind that lifting too much too soon can lead to failure and injury.

10. Not performing the exercise properly. Only one proper way exists to perform a specific exercise. As such, you should always adhere to the correct technique when strength training. If you compromise the recommended mechanics for doing an exercise, you will compromise your results.