The REAL Story on Lactic Acid

How about the REAL story on lactic acid?

In sports, lactic acid build up is always seen as the "bad guy". Every time our muscles stop working and start to burn we immediately blame it on the lactic acid.

Originally, it was believed that lactic acid was responsible because it is a byproduct of energy metabolism that would fill all of the space within the muscle tissue and weaken the electrical impulses that cause the muscle to contract.

Now, more and more, it is becoming common knowledge that the lactic acid build up which was thought to hinder the muscle movement is actually utilised as energy aerobically. Especially if training targets this energy system. It is actually the hydrogen ions released from the lactic acid that cause the loss in performance.

The point at which exercise intensity is so high that the lactic acid being produced is faster than the hydrogen ions it releases can be metabolised from binding to a sodium or potassium ion and producing lactate is known as Lactate Threshold (LT), or Anaerobic Threshold (AT), and it is at this stage where performance is jeopardised.

The aim of lactate or anaerobic threshold training is to more efficiently metabolise lactate in order to prolong and suppress the build-up so you can go harder and faster for longer.

"Since the 1970's, a 'lactate revolution' has occurred. At present, we are in the midst of a lactate shuttle era; the lactate paradigm has shifted. ...lactate acidosis is being re-evaluated as a factor in muscle fatigue."— L.B Gladden, 2004

Check out this journal by L.B Gladden from The Department of Health and Human Performance:
Lactate metabolism: a new paradigm for the third millennium

Source: The Journal of Physiology, 2004