Good pain is experienced as a short term burning sensation that lasts usually a few seconds and up to 3 minutes depending on each persons particular recovery time. Good pain may experience a stiffness and soreness following an exercise routine and can last up to 36 hours after exercise.
This pain is the result of A) micro tearing of muscle fibers which is necessary for muscle growth and /or B) the accumulation of lactic acid (the by-product of muscle energy) which is stored in the belly of the muscle until our body can rid itself of this waste product.
Good pain should the only be felt in the MUSCLE or MUSCLES being exercised and never, ever in other locations such as antagonistic muscles or worse.... the surrounding JOINTS.
Clinically, there are three stages of any condition that separates an injury from good pain.
First is called "ACUTE" pain which is usually sharp pain that creates immediate cessation of the movement that caused it. The body has only instinctive reactions to this pain and will do almost anything to protect us from ouselves. This pain lasts anywhere from minutes to up to 72 hours.
"SUB-ACUTE" pain is a condition where the pain experienced in the acute stage either increase in intensity or remains at current levels but can last up to 6 weeks. Often this is the worst of the conditions because our bodies adaptability screens the pain levels and we continue to perforn activities which create a vicious cycle of re-injury and no heal time. Many times we medicate ourselves in this stage and trick ourselves into believing that we are improving and we can continue on with our workout. This is the stage where you will hear yourself saying "of course it hurts but that is just the price of working out" or "I ain´t no sissy...I can handle a LITTLE PAIN!"
The third stage is "CHRONIC" pain. This, too, is tricky because either you never humbled yourself enough to see a physician and find out what and why your hurt or your simply have learned "to live with it." This stage begins after 6 weeks of consistent pain and can last for years if gone untreated or at least un-CONFRONTED!
We are stubborn beings, that is for sure. We are egotistical and cannot bear the thought that we are not INVINCIBLE. The pain of missing a few workouts and listening to your body is sometimes greater than the pain you are experiencing physically. This is a dangerous stage thats sets up degenerative changes in your body, especially your joints, and can lead to either disabling situations, permanent medicating, joint replacement or any combination of the above.
Workouts should be fun and beneficial...or else they should not be done. While the benefits of exercise... mentally, emotionally and physically are innumerable, there are life lessons to be learned all during the process of workouts, too. Controlling our ego, stabilizing our stubbornness, and learning to dance with our body instead of forcing it to do things that nature sometimes is telling us not to do - those are the keys.