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.

The fallacy of static stretching

Perhaps it's time to re look what happens when we stretch.  You can read the full article Science of Running.  A brief summary. We are bombarded with the words stretch, every thing from stretching helps to remove lactate (more on lactate in a coming post), stretching make you run faster, makes you less prone to injury's bla bla bla.  Dont get me wrong stretching has a place at the right time, and then it is a question of static or dynamic.  But there is research that suggests stretching reduces running economy and would likly hold true for other sports also.  The main idea and research is that the bodys tendons act like a spring, each time when the foot hits the ground the spring is loaded and absorbs the energy from impact, and then a moment later the energy is released to let you jump, run or sprint further.

In a similar way the muscle could be looked at as a elastic band, a new elastic band is fairly springy and has lots of energy stored within which will spring back, as where a stretched out band won't have the same elasticity.  So what this means is the athlete that stretched before he started his plyometric session or run is less economical when you apply the elastic ban principle to muscle.

Here is a short article from FaCT Canada on stretching.  And here are the links to the research if you havnt already read the full article at Science of Running,  Research 1  Research 2 Research 3.

The FaCT way of looking at the body!

I have a keen interest in the FACT - Feldmann and Chlebek Testing System, mainly their way of looking at the athletes body from a alternative angle to the usual University text book answer.  Instead of only looking at lactate as a marker of performance/fatigue one should look at the process that is going to lead to the "lactate threshold point" or as FaCT test it LBP (lactate balance point).

The body has three trainable systems: The heart, the lungs, the muscle. Did I just say lungs? yes the lungs are trainable in the same way the heart and muscle is.  More on that topic in another post.  Each person has a weak link in their body. Some have strong lungs but weak muscle system, others strong heart weak lung system etc.   FaCT calls this weak link the limitation or limiter.

Your body will only go as fast as the weakest link, at some point your body is going to have one of the other two main systems that is going to compensate for this limiter.  So if your respiratory system is weak then there could be a poor gas exchange, the diaphragm is weak then you could for e.g. start having a lower TV (tidal volume) and a increased breathing rate.  The heart might compensate by increasing the cardiac output which will increase heart rate to compensate for the loss in incoming oxygen or not getting rid of the CO2 in the gas exchange.  At the LBP your CGM (Central Governor Model, Noake's) is going to "kick in" to save the body's vital organs.  Similar will happen if you have a muscular limitation.  Either there isn't enough capillarization, mitochondria etc which could affect muscle utilization of the oxygenated blood to the muscle. once again there will/should be a compensator such as lungs or heart.

The body can only go as hard and fast as it's weakest link before the CGM or ECGM, metaboreflex etc "kicks in".

Each athlete will have a different limiter, and the same workout for two athletes will have a different training effect based on the above.  This is why some training programs will work for some athletes and not for others, as the coach hopes that he's workout is training VO2 meanwhile athlete 'A' has a muscle utilisation problem so will never stress his VO2 while athlete 'B' has great utilisation but a VO2 weak link so will benefit from the VO2 session.  Are you starting to see the picture?  The coach has 5 athletes but only 2 improve and he wonders why!

The FaCT solution to this problem is to test the body for the three trainable systems the FaCT way  and then to train the weak link without guessing and hoping hopelessly that a programme that has worked for 60% of athletes over the past 20 years will work again.  Here is a short article on the limitation subject from another athlete Rethinking current exercise physiology.