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  • "Coaches have understood things scientists didn't"

    New York Time's article on the misunderstanding of the role of lactic acid


    http://www.nytimes.com/2006/05/16/healt ... ei=5087%0A

  • #2
    Re: "Coaches have understood things scientists didn't&a

    Originally posted by just4fun
    New York Time's article on the misunderstanding of the role of lactic acid
    I'm sorry but i do not buy Dr. Brooks explanation at all. He is claiming that the lactate can be used as a fuel source. And there is no doubt that this is true but NOT without oxygen. So this brings us right back to square one. No oxygen-->anaerobic--> lactate build up.

    Given this, i have no idea why Dr. Brooks would say "Scientists said, 'You're anaerobic, you need more oxygen, but they were stuck in 1920." (paraphrased from the article) Even with his ideas it is still true to say 'You're anaerobic, you need more oxygen'

    What his results do indicate is that once aerobic conditions return, during recovery, then the lactate can be used inside the cells as an energy source rather than entering the blood as a waste product. Consequently a trained athlete should be able to remove lactate from the system faster.

    This new metabolism of lactate does not mean it is an efficient fuel source that benefits athletes in anaerobic conditions (as the article and Brooks seem to imply). There was a much better study published a few years ago that showed that there was a positive effect of lactic acid that allowed muscle cells to function for longer than expected in anaerobic conditions (see below). However, this is not what Dr Brooks is claiming.

    I'll be interested to see what Figo makes of this.

    The more interesting paper is:
    • Intracellular Acidosis Enhances the Excitability of Working Muscle
      Thomas H. Pedersen, Ole B. Nielsen, Graham D. Lamb, and D. George Stephenson
      Science 20 August 2004: 1144-1147
    This paper shows that lactic acid can help muscle activity (helping them generate more force) even as they fatigue in anaerobic conditions, by altering the activity of chloride channels.

    Comment


    • #3
      ]Daisy, just let it go.

      The old school is wrong and has been wrong for a long long time.

      "O2 availabity = good, / blood lactate production,accumulation = bad" is just misguided, simplistic thinking. It is the single idea that has held back US distance running more than any other.

      Comment


      • #4
        Originally posted by dsrunner
        It is the single idea that has held back US distance running more than any other.
        And all this time I thought it was because we didn't have any good distance runners!

        Comment


        • #5
          Originally posted by dsrunner
          "O2 availabity = good, / blood lactate production,accumulation = bad" is just misguided, simplistic thinking.
          I never disagreed with this. What i said was that the lactate cannot be used as a fuel source without oxygen. As i pointed out there are other physiological/cellular reasons that could offer a better explanation for why lactate is not bad. It has nothing to do with it being a fuel for the muscles as Dr. Brooks claims.

          Comment


          • #6
            Daisy is absolutely correct.
            "A beautiful theory killed by an ugly fact."
            by Thomas Henry Huxley

            Comment


            • #7
              Pego is absolutely correct.

              Comment


              • #8
                Study the Krebs Cycle.

                Which is better, 2 bits of ATP for use or 36 (32, 34, 38--whichever, I'm not near my textbooks right now).

                This guy's thoughts on mitochondria and mitochondrial protein are more interesting.

                Comment


                • #9
                  Originally posted by Brian
                  Study the Krebs Cycle.

                  Which is better, 2 bits of ATP for use or 36 (32, 34, 38--whichever, I'm not near my textbooks right now).

                  This guy's thoughts on mitochondria and mitochondrial protein are more interesting.
                  So which part of Dr. Brooks hypothesis do you think is more interesting and accurate than what is in the text books?

                  While we're at it which do you think is more efficient for the cell?
                  • pyuvate --> acetyl coA (the usual path leading to cellular respiration)

                  or:
                  • pyruvate --> lactate --> pyruvate --> acetyl coA (the path for respiration using mitochondrial lacate dehydrogenase)


                  Then, when there is no oxygen, how will the acetyl CoA be used by the Krebs cycle?

                  Or, how will the NADH that results from the lacate dehydrogenase catalysed reaction in the mitochondria (lactate + NAD --> pyruvate + NADH) be oxidised by the electron transport chain without oxygen?

                  Krebs cycle and electron transport chain are useless without oxygen. Remember that Dr. Brooks is very specific when he says "Scientists said, 'You're anaerobic, you need more oxygen, but they were stuck in 1920." What did he mean when he said this?

                  Comment


                  • #10
                    I have tried to determine what Dr. Brooks is really trying to say. Here is a better article that is one step closer to the horses mouth;
                    http://www.berkeley.edu/news/media/rele ... tate.shtml

                    At least in the Berkeley article it does not talk about science being stuck in the 1920's with respect to the cells need for oxygen during anaerobic conditions. However, it does talk about lactate as if it is being made as a special fuel to feed into the mitochondria. He has no evidence that lactate is made for this specific purpose. What advantage does a cell have to make lactate rather than shuttling pyruvate directly into the mitochondria if an athlete is working aerobically?

                    Brooks also says that the mitochondria are clearing lactate from the muscle cells during 'aerobic exercise' and this is beneficial for an athlete since lactate is removed more efficiently (this seems to be his major conclusion). This could be good for two reason 1) lactate is removed more quickly from the cell after anaerobic metabolism, 2) the energy from the lactate is not lost from the cell (this could be an issue for longer distance athletes to help conserve skeletal muscle glycogen). I think this latter part is his big idea with respect to helping athlete performance but I see no published evidence that making lactate is a preferred pathway during aerobic exercise (Brooks claims this).

                    The dispute seems to be that he thinks lactate is produced to satisfy the high energy needs required by the cell during aerobic exercise. He cites the fact that mitochondria can metabolise the lactate as proof. His critics probably argue that the lactate is a product of cells being anaerobic (prolonged or transient) and the mitochondria are then removing it from the system. In the latter scenario lactate is still a waste product of anaerobic respiration.

                    Comment


                    • #11
                      Despite a number of scientific degrees, I am not that keen on biological processes. However, as a "reformed" quarter-miler, I can say that no amount of new research is able to make a muscle flooded with lactic acid work efficiently. Ancecdotal, and light-hearted, comments aside, I think Daisy is spot on with this. Many things can be burned as fuel, but not all with the same degree of efficiency.

                      Comment


                      • #12
                        lance armstrong

                        during the tour de france "up close and personals" they made a big deal of lance armstrong's blood testing in training for lactic acid and recovery. Does any of this debunk what he is capable of doing chemically (no pun intended) when it comes to his lactic acid levels before and after climbs. I don't understand a thing abouty this......

                        Comment


                        • #13
                          Re: lance armstrong

                          Originally posted by kling
                          during the tour de france "up close and personals" they made a big deal of lance armstrong's blood testing in training for lactic acid and recovery. Does any of this debunk what he is capable of doing chemically (no pun intended) when it comes to his lactic acid levels before and after climbs. I don't understand a thing about this......
                          I don't think it debunks this at all.

                          There are two variable here. The number of mitochondria in each muscle cell and the amount of lactate dehydrogenase activity per mitochondria. It makes sense that trained athletes (or genetic freaks) will be on the high end of the scale for both.

                          Anyone who is training will increase the number of mitochondria in the muscle cells since they are the power source needed for muscle contraction during aerobic activity. Use the muscle more and it makes sense that the muscle cells will adapt. What Brooks work is showing is that there is another factor that is important too, the ability for the mitochondria to metabolise the lactate produced during anaerobic bursts. My guess is that athletes that have high levels of mitochondrial lactate dehydrogenase will recover much faster from anaerobic activity as well as use the muscle energy stores more efficiently. All this has to be a good thing for hill climbing with bursts of anaerobic excercise followed by aerobic recovery periods.

                          Take home message: More mitochondria are good for making energy, more lactate dehydrogenase is good for recycling lactate (which means more efficient use of the muscle cells resourses as well as faster recovery from anaerobic excercise).

                          So what new ideas has Brooks contributed to the field based on his publications? As far as I can tell most people thought that almost all the lactate was lost from muscle cells to the blood. Brooks has shown that this loss is not so great since the muscle cells can recycle it for energy during aerobic respiration. This is an advantage since the muscle cells limited energy stores are used more efficiently after anaerobic exercise. It is also a more efficient way to remove lactate from the cell.

                          How does this relate to interval training? Removing the excess lactate after anaerobic respiration is desirable for optimal function. If the muscle cells themselves can do this by recycling the lactate to pyruvate then this is a significant advantage since the lactate can also be used to make energy during the aerobic recovery, rather than be lost from the cell as a waste product to the blood. Interval training might increase the amount of lactate dehydrogenase in muscle cells such that athletes can recover faster from the anaerobic conditions during the aerobic phases.

                          Comment


                          • #14
                            Re: lance armstrong

                            Daisy,

                            In laymen's terms, what should I do differently in my training for distance running as a result of this new research, and/or what are "we" doing wrong? Thanks!



                            Originally posted by Daisy
                            Originally posted by kling
                            during the tour de france "up close and personals" they made a big deal of lance armstrong's blood testing in training for lactic acid and recovery. Does any of this debunk what he is capable of doing chemically (no pun intended) when it comes to his lactic acid levels before and after climbs. I don't understand a thing about this......
                            I don't think it debunks this at all.

                            There are two variable here. The number of mitochondria in each muscle cell and the amount of lactate dehydrogenase activity per mitochondria. It makes sense that trained athletes (or genetic freaks) will be on the high end of the scale for both.

                            Anyone who is training will increase the number of mitochondria in the muscle cells since they are the power source needed for muscle contraction during aerobic activity. Use the muscle more and it makes sense that the muscle cells will adapt. What Brooks work is showing is that there is another factor that is important too, the ability for the mitochondria to metabolise the lactate produced during anaerobic bursts. My guess is that athletes that have high levels of mitochondrial lactate dehydrogenase will recover much faster from anaerobic activity as well as use the muscle energy stores more efficiently. All this has to be a good thing for hill climbing with bursts of anaerobic excercise followed by aerobic recovery periods.

                            Take home message: More mitochondria are good for making energy, more lactate dehydrogenase is good for recycling lactate (which means more efficient use of the muscle cells resourses as well as faster recovery from anaerobic excercise).

                            So what new ideas has Brooks contributed to the field based on his publications? As far as I can tell most people thought that almost all the lactate was lost from muscle cells to the blood. Brooks has shown that this loss is not so great since the muscle cells can recycle it for energy during aerobic respiration. This is an advantage since the muscle cells limited energy stores are used more efficiently after anaerobic exercise. It is also a more efficient way to remove lactate from the cell.

                            How does this relate to interval training? Removing the excess lactate after anaerobic respiration is desirable for optimal function. If the muscle cells themselves can do this by recycling the lactate to pyruvate then this is a significant advantage since the lactate can also be used to make energy during the aerobic recovery, rather than be lost from the cell as a waste product to the blood. Interval training might increase the amount of lactate dehydrogenase in muscle cells such that athletes can recover faster from the anaerobic conditions during the aerobic phases.

                            Comment


                            • #15
                              Re: lance armstrong

                              Originally posted by kling
                              Daisy,
                              In laymen's terms, what should I do differently in my training for distance running as a result of this new research, and/or what are "we" doing wrong? Thanks!
                              Nothing. Brooks is saying the coaches always had it right (and I agree with him). But his biochemical reasoning for that comment is wrong.

                              Comment

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