Oooooh... those sore muscles!

True or False?  Muscle soreness is caused by a buildup of lactic acid.  False!

For years coaches and athletes have blamed lactic acid buildup for post-workout soreness.  Lactic acid has not only been incorrectly identified as the cause of muscle soreness, but in fact, it can actually be used as fuel for your working muscles.

Your body needs energy to function and glucose is its primary fuel source during exercise.  Your body uses a process called glycosis to break down glucose into a substance called pyruvate.  Without delving too far into the science, the pyruvate is then converted into adenosine triphosphate (ATP) which is a usable energy form.  This whole process requires oxygen.  So at times when there is not enough oxygen available, such as during intense bouts of exercise, your body is unable to produce enough ATP to meet its energy demands.  This results in an overproduction of pyruvate which is then converted to lactate.  Still, this lactate differs from LACTIC ACID.  Lactate is missing a proton, is not acidic, and is therefore not the cause of the burning sensation in your muscles.

So if it's not lactate or lactic acid, what does cause muscle burn?  The ATP that your body is using as a fuel source produces a proton.  As these protons build up, the area becomes more acidic. These protons come into contact with the nerves near the muscles and as a result create muscle burn. 

Just as lactic acid cannot be blamed for the muscle burn during exercise, it is also not responsible for the muscle soreness post-exercise.  The post-exercise muscle soreness that you feel is due to microtrauma to the muscle fibers.  In the hours after the microtrauma occurs, your damaged muscles become swollen and release chemical irritants which can stimulate pain receptors.

There are several things you can do to help ease the pain and heal those sore muscles.  Gentle stretching helps stimulate circulation.  Stay hydrated and pay attention to good nutrition.  Choose lean proteins to help rebuild muscles and complex carbohydrates to help replenish those depleted glycogen stores.  Finally, as we have emphasized many times, gentle movement will help increase blood flow to your muscles and will aid in healing...  so walking or gentle cardio is the perfect recovery day exercise.