If you are sore after working out, you might wonder what is causing you to ache.  It is widely believed that muscle pain and soreness after working out is caused by a build up of a muscle by-product known as lactic acid.  This by-product builds up and irritates muscles until it is “sweated out” through the skin or otherwise removed (a hot bath with baking soda is recommended for leaching the acid out).  Over the past few years, though, we have learned that this is not true. 


Muscle soreness after working out is caused by micro-trauma to the muscle fibers.  This micro trauma (caused by working hard) causes calcium molecule leakage from these muscle fibers as well as an accumulation of histamines, potassium, prostaglandins, and local edema.  The painful sensation come from pressure placed on the muscles due to fluid retention in the muscle area.  The localized edema (fluid retention) puts pressure on the muscle’s nerve endings, causing a sore sensation.  The soreness is not caused by damage to the muscle itself (except, perhaps, if your muscles are not sore, but in extreme pain). 


The muscle soreness that you are feeling could be an indication of muscle growth.  Light training in the same exercise as well as stretching sore muscles can help to decrease the soreness.  It is also okay to train and/or use your sore muscles, even before they feel totally better as long as you do so with caution and care.  Damaging muscles seriously will not lead to gaining strength.  Improvement in muscle performance (this means increased strength, control and endurance) comes from stress and recovery.


So should you stop before you “feel the burn”?  Research indicates that you should not unless you are not looking to improve.  When you work your muscles hard, your body goes to work about eight hours later.  Your cells release cytokines that cause inflammation (and soreness), increased blood flow (redness) and increased fluid flow in the damaged area (causing swelling).  The cells around the damaged area release factors to encourage tissue growth to heal the damaged muscle fibers.  Muscle fibers become larger each time, and sometimes grow in number by splitting to create new fibers. 


Eventually your muscles will not be sore anymore from the same old routines.  You may be thinking that this is a great thing, and you are partially right.  Your muscles have grown to the point where they are no longer overworked and therefore damaged with micro-tears from your regular workout routine. If you are happy the way you are, then keep up the routine and revel in the lack of pain.  This will only ever be maintenance routine, however, from the time that pain and soreness cease.  As you read above, muscles grow by building upon damage caused by your workout.


You will never become stronger by performing the same routine that has stopped causing you to become sore.


Now that we have told you what a great thing it is to be sore, here are a few things that you can do to at least reduce the pain.  Warm up before your workout and cool down afterwards.  Stretch when you are finished.  Start a new exercise gradually and build up.  Avoid making sudden major changes to anything in your routine.  Introduce new things slowly and work up to your max. 


Are you already sore?  Avoid vigorous activity that causes pain, and use the RICE method if you are very sore.  Do some low impact aerobics to help increase blood flow.  Gently massage the affected muscles, and stretch them gently, too.  If your pain is bad, try taking an anti-inflammatory painkiller like ibuprofen.  And the best thing you can do for a sore muscle?  Give it time to heal.