There are two common mistakes that many resistance training newbies make: 1) Lifting more weight than they can handle, and 2) Not maintaining proper form throughout their set.

With regard to the former, it seems like this is a problem typically relegated to teenage guys. In my post "The 10 People You'll Find in Any Gym," you'll see these guys labeled as the Teen Titans. Basically, their bodies are in a state of rapid change, with the one positive effect of that hormonal upheaval being the introduction of bigger and stronger muscles. Trying to sustain this growth (and to impress a few cheerleaders in the process), these teen guys start hitting the gym. However, things sometimes go awry when they lift weight that is too heavy for them. This mistake leads directly to point #2, as form and technique pretty much get tossed out the window.

To prevent injury, it is imperative that proper form is strictly adhered to. Bending, contorting, twisting and swinging weights and/or your body in efforts to complete another rep is a sure-fire way to hurt yourself. Furthermore, cheating in this manner mitigates the muscle-building effects of the exercise itself.

While I point to teenage guys as being the chief offenders of these two rules, there are plenty of men and women who make these same mistakes. Remember, No Pain No Gain is not really the best tenet on which to base your workout, especially when that pain is coming as a result of damage to your body.