Ever wondered why some training programmes work for some athletes and not for others? Why some people are genetically gifted athletes? Why there is a fixed set of intervals for all athletes? Why certain drugs work for some and not others? Do compression socks work? What the hell does a VO2 max test tell you, is it just useless information? Is lactate friend or foe? I delve into the sport science world and try to find the answers to train smarter and hopefully become a better athlete. This page is written in my own thoughts and words with a cross-pollination from several other sites and links to the original articles. Some of it might sound like a rant but it is written to make you think. So if you read it without a open mind then your in the wrong place. Enjoy and open your mind.

Sunday, September 5, 2010

Lactate fuel or foe?

Myth:  Lactate causes fatigue. Fact:  It corresponds with fatigue but does not cause it. In fact it is a mechanism to help delay fatigue. I will try to explain what lactate is and let you navigate to the links to understand how lactate is formed. Lactate has had a bad wrap over the years and even though it is proved that it is not the cause of fatigue people still believe that the burn is associated to lactate!  Or on TV a commentator might comment "look at that cyclist he's unclipped his foot from the pedal and shaking the lactate out of his legs" Wow! there must be a stream of lactate on the asphalt to sweep up!

Lactate is part of the Cori Cyle.  Lactate is hugely affected by the amount of glucose in the body.  A carbo low diet will have a lower lactate level than for the same intensity when the body is carbo loaded.  So lactate is rather a indication of fuel in the body. 
  • Lactate gets produced to help to retard acidosis.  (Acidosis is thought to be the cause of the burn).  
  • Lactate goes through the Cori Cyle and is converted back to pyruvate and then glucose  where it is used as a fuel again.
  • The heart and brain prefers lactate as a fuel!!!
So based on the current research lactate is essential to fuel the body. Still doubting if it is so bad?

Traditionally athletes cool down after a hard session to get rid of lactate.  If lactate is such a important fuel in the body is it wise to cool down after or between hard session when the heart and brain needs this fuel and you are using more glucose to go for the cool down which could be used for recovery? Perhaps what the body is rather doing during a cool down is to get rid of excess CO2, pumps oxygenated blood back to the muscle and simply metabolises lactate back in to fuel! I don't know the full answer to not cooling down, its a question that was discussed by FaCT  see the discussion here! but once you understand the inter functions of the body one can start challenging traditional ideas.

Here is a easy to read article on lactic acid.

Here is a in depth look at the Biochemistry of Lactate Metabolism
It will help to have a chemistry back ground to fully understand and appreciate the article but reading past the formulas one will still understand the article.

You can find many more on this and other topics in the FaCT Canada discussion.

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