Posted by Frank Day (63.201.228.13) on January 23, 2004 at 09:04:08:
In Reply to: Re: How is this for a thought? posted by Cris LaBossiere on January 22, 2004 at 12:56:02:
: I have to say that I disagree with this theory. It is well established through research that the ability to clear lactate and or tolerate muscle acidity is largely determined by o2 availability, lactic acid transporters (increase with training), lactate buffering, and other factors including mitochondrial hypertrophy and greater cross section of sarcoplasmic reticulum. This is well established and understanding in this area is likely to continue to substantiate this.
Of course the ability to clear lactate is associated with O2 availability since lactate comes from anaerobic metabolism and O2 avaialbility is associated with capillary density. However, I don't understand why you say the ability to tolerate muscle acidity is associated with this. Makes no sense to me. Muscle acidity is not tolerated because it changes conformation of proteins and enzymes making them less efficient at doing what they have to do to make the cell work. This is initially handled by buffering using the bicaarbonate system primarily. I am not aware that athletes are able to modify through training (or any other means) their buffering system or modify proteins to react differently to an acidic environment.
: Neuro patterning is more connected with mechanical efficiency, where “wasted energy” is measured in poor muscle firing sequence (some muscles working “for” the movement others moving “against” the movement, etc). While this will influence working muscles and therefore the aerobic/ anaerobic continuum, the coordination influence will be quite small compared to physiological and chemical adaptations influencing lactate clearing and lactate tolerance.
It sounds like you are mixing apples and oranges here. I submit that mechanical efficiency and neuro firing patterns go hand in hand. I believe that PC's have shown this to be quite large in the overall gains available to the athlete, much larger than any gains available from training the ability to tolerate lactate. What my original post tried to say is that if one was using all of the muscles equally, then when one did go anaerobic, all of the muscles would enter this phase at the same time, and the resulting lactate load would be greater and the measured lactate levels should be greater. It seems to me that measured lactate levels indicate the more the amount of muscle mass that is anaerobic rather than how well the athlete has trained him/herself to tolerate the acidic environment. For the reasons stated above, the later "concept" makes no sense to me.