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     Juerg New member Username: Juerg Post Number: 66 Registered: 04-2006 |
We had some very interesting internal questions , thanks to recent discussion on this Forum , concerning lactate. It may be time to do a short "historical" review on this subject, based on own expirence with lactate - and performnace testing over the last 35 years as an athlet,a student, as well as a coach and a "hobby " researcher, in combination with some research back in the existing literature. Reviews by Roberge, Brooks, Gladden, Kindermann, Mader, Hollman,Simons a.s.o ) to name some of the many researcher, who contributed to the immense amount of testing and informations, will show some interesting development ( trends) in where we come from , where we may stuck and where we may go from here. The immense interest on the north american continent over the last 10 years in lactate testing shows, the fast change in the field, where lactate is used or abused. We from FaCT , and certainly Herb has one of the better, if not best inside information , who is using lactate testing and how much, thanks to the main distribution ship and connections he build up over the years with National teams and Universities alike. Over the last 100 years there was a trend of some major shifts in the way we were "treating" lactate. For the most of the last century lactate was often considered as a waste product of metabolic steps (glycolysis due to an oxygene deficit or O2 dept caused by intense exercises ( hypoxia) and therefor it was considered as the cause of muscle fatigue and last but not least a key factor in acidosis-induced tissue damagage. Now this was "standard " believe till the end of the 70's, but stuck in literature, research papaers all over the world till this days, and is still the key element for many of the current coaches and testing systems. End of the 1970 a "lactate revolution" ( Gladden) has occured. I remember the Italian rowing team in Silvaplana , using lactate completely different , than the ( Mader) 4 mmol concept used by the German groups. We did some own testing and had some very heavy and interesting discussion at that time, concerning the numbers 2 and 4 mmmol. I remember top runners ( marathon - 2.12 ) who never ever could produce 4 mmol in the testing Lab, so we just did some " extrapolation" and he jsut did not had it at that spec, day ( not fighting enough. I remember this athlet very well, how mad he always was, and finally refused to be tested , because of this and his personal feeling , which nerver was in any way close to the recommandation he got from the science lab.. We will see in some follow up infos , how the different "areas " of lactate and the idea , how it may work have changed. The interesting story is, that we seem to always run behing by about a generation , in the way we accept this new directions, assess them and finally try to implement them in the practical world. One of the main reasons is perhaps , the way our coaching education , and the education system as a whole is organized. We have a "classroom " approach , and a "teacher" , who has the goal or the duty to reach a certain goal. He has to bring the athlet to a certain point, so he decides the goal and the outcome. We are not assessing the individual as an individual, taking and stating from where we are and developping to where we are perhaps able to go. We throw everybody in one basket and mix it , and see where we end up. Most practical example are group rides in clubs , as well as group organized national team training camps, where everybody likes to train with the top gun. Well take some time here whether and how we go from here, and go back to your last trainingcamps and rethink the effect of that camp. So will see you later on this thread with some summaries about the "lactate history .: Juerg | ||
| Juerg New member Username: Juerg Post Number: 67 Registered: 04-2006 |
Here is an interesting start into the lactate "history ." For interested people this is worthwhile to read, otherwise check our summary of different infos and articles. " Lactate metabolism - a new paradigm for the third millennium. " By L. B. Gladden published online May 6 2004 The journal of physiology. Here the abstract : " For much of the 20 th century, lactate (La-) was largely considered a deadend waste product of glycolysis due to hypoxia, the primary cause of the O2 dept following exercise, a major cause of muscle fatigue, and a key factor in acidosis-induced tissue damage. Since the 1970's a "lactate revolution" has occured. Presently, we are in the midst of a lactate shuttle era; the La- paradigm has shifted. It now appears that increased La production and (La-) as a result of anoxia or dysoxia are often the exception rather than the rule. Lactic acidosis is beeing re-evaluated as a factor in muscle fatigue. Lactate is an important intermediate in the process of wound repair and regeneration. The origin of elevated La in injury and sepsis is being re-investigated. There is essentially unanimous experimental support for a cell-to-cell lactate shuttle,along with mounting evidence for astrocyte-neuron,lactate-alanine,perixso mal,and spermatogenic lactate shuttles. The bulk of the evidence suggests that La is an important intermediary in numerous metabolic processes, a particularly mobile fuel for aerobic metabolisme, and perhaps a mediator of redox state among various compartments both within and between cells. La can no longer be considered the usual suspect for metabolic "crimes", but is instead a central player in cellular, regional, and whole body metabolism. Overall, the celkl-to -cell lactate shuttle has expanded far beyond its initial conception as an explanation for muscle and exercise metabolism to now subsume all of the other shuttles as a grand description of the role(s) of La in numerous metabolic processes and pathways. " This abstract is one of the stronger "proves" of the citical assessment needed to overcome tests with absolute numbers ( 2 / 4 mmol Mader ) as well as any attempt to try to define so called lactate thresholds as a way of producing intensity zones , based on numbers and % tige. The question of production and "re-cycling " of La in the cells , shuttle from one place to another, re-cycling in other places, distribition and using in the same place, all of this will show the "inaccuracy" of accurate measuring with numbers, and other "fixed" values. One more reason to take a closer look to FaCT and the idea of trend versus numbers. As we mentioned in a lot of topiscs, we use lactate for more than testing for intensities , but as well for recovery , overload of muscles , and chnages in ebergy distribution bevor, during and after exercising. . With this in mind we look forward to some summaries in lactate "history ". Cheers Juerg | ||
| Juerg New member Username: Juerg Post Number: 71 Registered: 04-2006 |
Part 1. Review of lactate history. By L. Gladden " In 1950, von Mural distinguished 4 different eras in the development of muscle chemistry: - pre- lactic acid - lactic acid -phosphorylation -myosin. The pre-lactic acid area began in 1808 with Berzelius' discovery of an elevated concentration of lactate in " the muscles of hunted stags ' ( Brooks and Gladden 2003 ). Although there were several studies of lactic acid (HLa) in the next 99 years)Brooks and Gladden 2003 ) confusion reigned until the landmark studies of Fletcher and Hopkins (1907). Their paper ushered in the lactic acid era during which A.V. Hill's studies suggested that HLa was the immediate energy donor for muscle contractions and Meyerhofer demonstrated that glycogen was the precursor to lactate ( 1920 ) Between 1926 and 1932 , ATP and PCr were discovered and investigations were begun to determine which of these phosphagens might be the direct energy donor for muscle contraction ( Brooks and Gladden 2003 ). These discoveries and new ideas changed the field of muscle energetics so profoundly that A.V. Hill (1932) called the experiments over the 1926-32 time period , " the revolution in muscle physiology." Accordingly, the 1930's marked the beginning of the phosphorylation period of muscle chemistry. In 1939, the myosin period began with the finding that the enzyme responsible for ATP hydrolysis was assocoated with the muscle protein, myosin ( Mural 1950 ) By the early 1940's the full Emben-Meyerhof (glycolytic ) pathway had aslo been elaborated. If we restrict our consideration to HLa and its metabolism, we might term the period from the 1930's to approximately the early 1970's the "deadend waste product era . " During this period, La was largely considered to be a deadend metabolite of glycolysis resulting from muscle hypoxia ( Wasserman 1984) Lactic acid was also believed to be the primary cause of the slow component of the O2 dept ( Margaria et al 1933) and a major cause of muscle fatigue ( Hermansen 1981). Since the early 1970's a " lactate revolution " has occurred. Presently, we are in the midst of a lactate shuttle era which began in 1984 with the introduction of the lactate shuttle hypothesis by George Brooks ( 1985a)." As you can see out of this short introduction by Gladden, we are on the one side in midst of some realy interesting timesconcerning lactate values and information, but on the other side we are in th public , as well as often in the coaches area stuck prior to the lactate shuttle era. Listen to sport comentators and former active athlets commenting on the feeling of athlets on the race track. "See how the lactic acid is slowing the runner or speedskater down" . Or comments like on food supplements:" will reduce lactic acid build up. or will remove lactic acid faster." Massage infos as to massage the lactic acid out of the system or one of the interesting concepts in sport. " Lactic acid tolerance training." Or at the end of all the Discussion we started with Nik . About lactate threshold and testing of lactet thresholds or individual lactate thresholds. When we started in the end of the 1980 ) in preparation to the Calgary Wintergames , I remember some heated discussion we had with the Team physiological guy, where we questions the validity of the 2 and 4 mmol lactate concept ( Mader ), because 2/3 of the team could not train with this recommandation, and the athlets just endet up using body feeling instead of research info. So on the one side there was a lot of money invested for Lactate testing , but the connection from the research team to the coach/athlet team failed terribly. Is it better today ? Who is collecting for who and how is it used down to the base of actual practical training. We know now after over 15 years of FaCT development as a way of bringing "actual "physiological individual testing into the practical field, that most of the users of FaCT after some hundreds of test and practical work will see the immense benefit and info we can collect by using lactate not as an absolut value but as a perfect marker for metabolic changes before during and after workouts. The comparison of trends and values will open a whole new field of information and will change the way we are looking on training zones and adjustments. We are more and more convinced, that % of some maximum , as well as % in general for fixed definition of training zone has only the advantage of "programming" training programs , but do not reflect the physiological changes , which alwasy will occured during training and rest periods and during the time of workouts, caused by age, change in fiber situations, technique and so on. We may have to think more dynamically and be ready to work on easy daily assessments to see early enough the changes which may be caused by interventions ( Training ) Once we are open to the fact , that 70 % or what ever % is only mathematically always 70 % but physiologically it is different inter-individual as well as intra-individual ,we may be able to reduce workout hours to gain more recovery hours to benefit better from all the stimmulation / relaxation concepts. With this in mind we may meet again here for some further inside views. Cheers Juerg | ||
| Juerg New member Username: Juerg Post Number: 72 Registered: 04-2006 |
Here is an example of what the discussion is n the lactate history. One of my sons is just writing tomorrow a Grade 12 biology exam. Page 121 Biology 12 ( nelson ) as part of the graduation Lit. in Ontario. The picture shows a marathon runner. The info to learn is : " Marathon runners are fatigued after a race because of the accumulation of lactate in their muscles. Panting provides the oxygen needed to respire the excess lactate. The accumulation of lactatemoleculesin muscle tissue causes stiffness, soreness and fatigue ....." So any idea what to tell him before he is fillig out the questions ??? Have a nice study Juerg | ||
| Juerg New member Username: Juerg Post Number: 73 Registered: 04-2006 |
okay here is the answer Andri will write today in his exam.. 1. He will write exactly what they ask for in the answer, using their words. with the comment. This is the answer because I like to pass the test. but here some addition for some thoughts I like to pass on , not to say , that this is the right answer as well, but to give some ideas about the relativity of grade 12 exams resp. grade 12 marks. Followed by some parts of the above ongoing discussion in a very interesting field with very interesting questions, but not as easy answers to pass as in grade 12. Andri wrote an essay with more or less the content on what education is . His summary was about. If you are able to repeat what you were thaught you have an education. If you are able to challange this you may have a brain. Have a good day. PS. What do you tell this kid as a father ???? Smile | ||
| Juerg New member Username: Juerg Post Number: 83 Registered: 04-2006 |
I know, I am somewhat behind on this topic so next on here will be a chapter out of L Gladden : "Lactate and O2 during exercise: I slactate an anaerobic metabolite ? Stay tuned for this one . Juerg | ||
| Juerg New member Username: Juerg Post Number: 84 Registered: 04-2006 |
Summary post from Andri Feldmann If lactic acid were split apart almost 99% would be dissociated into either La- or H+. Strenuous exercise causes a drastic jump in the values of these two substances. However, physiologists agree that fatigue is rather caused by the increasing H+ concentration rather than the La-. Numerous studies show that a decrease in pH will lead to a decrease in muscle function: 1. “reducing the transition of the cross-bridge from the low to the high force state” 2. “inhibiting maximal shortening velocity” 3. “inhibiting myofibrillar ATPase” 4. “inhibiting glycolytic rate” 5. “reducing cross-bridge activation by competitively inhibiting Ca2+ binding to troponin C” 6. “reducing Ca2+ re-uptake by inhibiting the sacroplasmic ATPase” All this sounds good and well, but in recent years the cause of fatigue has been challenged. Studies have surfaced that show that acidosis does not cause fatigue, but actually protects the working muscle. A new agent causing muscle fatigue is inorganic phosphate (Pi). The levels of Pi increase during intense exercise because of the rapid break down of PCr. Even this hypothesis is questionable because no studies have been done which take in account Pi levels along with pH shift and reduction of Ca2+. Furthermore certain questions do arise in regard to increased Pi levels. 1. Most PCr is broken down within 10 seconds of intense exercise, therefor would the role of Pi be restricted to this time frame? 2. “Can changes in Pi explain the reduction in performance observed in humans following prior intense exercise with different muscle groups?” A commonly misunderstood notion is that the production of lactic acid (because it is 99% dissociated pH) causes a continuos decrease in pH. However, things like H+ and HCO3- may be non-causative factors. “Instead, acid-base status is determined by the independent effects of carbon dioxide (PCO2), the concentration of weak acid buffers ([Atot], in plasma mainly the amino acids in plasma proteins), and the strong ion difference ([SID]). Another question raised is the contribution of La- in muscle fatigue. Until recently La- has been considered unimportant as a player in muscle fatigue, but numerous studies may say different. All these questions show that we may actually have very little intelligent information about what causes muscle fatigue and should consider this when we try to make sophisticated training plans. Reference: The Journal of Physiology: Lactate metabolism – a new paradigm for the third millennium. L. Bruce Gladden, J. Physiol. Published online May 6, 2004 http://jp.physoc.org/cgi/content/abstrac t/jphysiol.2003.058701v1 | ||
| Graydon New member Username: Graydon Post Number: 6 Registered: 11-2006 |
Hi Juerg, Just wanted to make a few points: Fatigue is a dubious term, and what will "cause" it greatly depends on how you define it. The mechanism of fatigue, exhaustion, volitional cessation of exercise, etcetera etcetera will be different depending on whether what terms we use, and whether we refer to whole-body fatigue vs. cellular fatigue, fatigue in a 1min (i.e. wingate) vs. fatigue in a 10min (i.e. VO2max) vs. fatigue in a 4-hour (i.e. prolonged activity) vs. 24-hour... and so on. So of course, it is perfectly correct to say H+ will both cause and not cause fatigue. As for lactate, yes, there is no such thing as lactic acid in living tissue. We only have lactate, which exists as a strong negative anion, the only strong negative anion which accumulates to a significant degree within the cell. Therefore, by the requirement of the law of electroneutrality, it must be met by an equal rise in positive charge, which is partially obtained from the dissociation of H+ from water. This is by definition the strong ion difference (SID) effect you mentioned above as an independent determinant of pH. So lactic acid - no; protons following lactate - yes. As for Pi (inorganic phospate), again we must remember the aqueous environment. Pi exists as the equilibrium sum of the diprontonated phosphate (H2PO4) with the monoprotonated phosphate (HPO4-, an anion) and therefore also a H+. In the same view that we see lactate is an important substrate and itself not the "acid", (though the protons that follow are), the similar situation follows that Pi is not necessarily the cause of fatigue (but that it leads to proton production as well). Pi, in fact, is an important stimulator of oxidative phosphorylation, and to a lesser extent, glycolysis. In that respect, we can be thankful for Pi (and ADP) for the maintenance of oxidative flux in the face of declining pH or PO2. As for PCr, even in heavy intensity exercise, the exponential time constant (~67% peak rise) of PCr decrement is on the order of 30s. So incorrect to say it is almost completely broken down in 10s. PCr is available and consumed even during an incremental exercise protocol lasting 15minutes, only then, at maximum work capacity and volitional exhaustion, has it decreased to nearly full depletion. The time course of PCr breakdown is stoichometric to Pi production, but remember that these are two separate reactions: the creatine kinase and the adenylate kinase. Lohmann referred to them as one, but they are in reality two distinct and separate reactions. Keep up the great discussion! Enjoy your holidays! Graydon | ||
| Nikoluski New member Username: Nikoluski Post Number: 16 Registered: 11-2006 |
"Lactate is a totally innocuous substance that, if infused into the bloodstream, has no noticeable effects." Noakes, T Lore of Running, 4th edition, 2004, pg 163 By examining muscle fatigue in rats caused by a reduced pH and loss of potassium, it was found that the “subsequent addition of…lactic acid led, however, to an almost complete force recovery.” “In contrast to the often suggested role for acidosis as a cause of muscle fatigue, it is shown that in muscles where force was depressed by high (potassium), acidification by lactic acid produced a pronounced recovery of force. Since intense exercise is associated with increased (potassium), this indicates that acidosis may protect against fatigue rather than being a cause of fatigue.” Nielsen O, Paoli F, Overgaard K. Protective Effects of lactic acid on force production in rat skeletal muscle J of Physiol 2001, 536.1, 161-166 "Many textbooks report that muscle fatigue is mainly the result of a decrease in pH within the muscle cell due to a rise in hydrogen ion concentration ([H+]) resulting from anaerobic metabolism and the accumulation of lactic acid. Recent literature, however, contradicts this assertion.” Stackhouse SK, Reisman DS, Binder-Macleod SA., Challenging the role of pH in skeletal muscle, Phys Ther 2001, 81(12), 1897-903 “…the increase in H+ (i.e. reduced pH or acidosis) is the classic cause of skeletal muscle fatigue. However, the role of reduced pH as an important cause of fatigue is now being challenged, and several recent studies show that reduced pH may have little effect on contraction in mammalian muscle at physiological temperatures.” Westerblad H, Allen D, Jannergren J. Muscle Fatigue: Lactic Acid or Inorganic Phosphate the Major Cause? News Physiol Sci 2002, 17, 17-21 Perhaps the real origin of fatigue is elsewhere... | ||
| Graydon New member Username: Graydon Post Number: 7 Registered: 11-2006 |
"Perhaps the real origin of fatigue is elsewhere..." The answer will never be well defined until "fatigue" is well defined. If you use 'failure to generate electrically evoked contractions in isolated/perfused frog/rat muscle' as your definition (as the studies alluded to above), sure, you may never see H+ as a major player. Conversely, in whole body studies, induced acidosis can impair performance (and induced alkalosis may be erogenic) for events lasting 1-10min. Here there is more than just a few muscle cells involved, and multiple sites for "fatigue": there is a cardiovascular system, and in particular a PNS/CNS, among others. Why else would you be interested in finding the "maximal" lactate someone can tolerate/generate/sustain during exercise, if there weren't some implication there that it is an indicator of events ultimately tied to 'fatigue'? | ||
| Juerg New member Username: Juerg Post Number: 85 Registered: 04-2006 |
Thanks to both of you guys for this inputs. For sure Graydon thanks for your short but clear answer. It is one of the points where a lot of practical "workers" like coaches and athlets are lost , but they are right., and Graydon made a very practical point in a very scientific way. There is the experiment in localized areas or muscles, and there is a whole physiological system behind. I will come back here witha comparison on fatgue as a "term " and "stress" as a term. What is Stress and what is fatigue ? Graydon already had the "weakness" in any discussion in this directions. Definition of fatigue. And for me the next strep is, implementing " fatigue a" as a tool of recovery training periodization.Fatigue level versusu performance level ( see. E. Banister ) So stay tuned for our next input. Juerg | ||
| Juerg New member Username: Juerg Post Number: 86 Registered: 04-2006 |
Okay , after some "heavy" information, packed with an inside view from Graydon , Nick and Andri, I like to go back to the "lactic acid" on the street and how we have different info to pass different tests. a) you remember Andri's Grade 12 exam and how heavy panting gets rid of lactic acid. Well he gave this anwser passed his exam. b) now my daughter Martina was back over Christmas and she just has to pass her test in Fitness and exercise physiology in Victoria. Here is her answer she has to give to be "certified " These are just some samples out of her exercise physiology book she has to learn from. On page 16 it starts not very promissing: Loss of training chapter. "If you stop exercise your muscles loses strength at a rate of about 5 % every 72 hours." Followed by Warming up. to increase core temperature and :" A warm up also increases heart rate and breathing rate allowing more oxygen to the working muscles and prevent lactic acid build up ." Well we are getting a much better picture on page 20. " Exercising at too high an intensity causes two problems: - Breathing becomes laboured as we strive to obtain more oxygen. -Lactic acid ( a by-product of anaerobic system) builds up in the muscles, causing fatigue and heaviness. Muscles can only tolerate so much lactic acid before they feel stiff and sore. At this point, the exercise must be decreased or stopped, or injury may occur." After that we have very clear info on , what fatigue is all about: "- Laboured breathing or gasping for breath because the muscles are not getting enough oxygen. -Pain or heaviness in the muscles from lactic acid. -Dizziness or nausea- oxygen supply short. -Stitch or cramp - the oxygen supply is short." Advice "don't ignore the symptoms of fatigue. Well at least we have a clear idea why it is working this way : Page 30 :" the presence of lactic acid in the system triggers pain receptors telling the brain that the body is low on oxygen. This stimmulates the body to breath deeper and more often- bringing oxygen into the system." Well there is at least light the end of that tunnel. Page 32 : " Following anaerobic activity lactic acid takes 1 - 2 hours to dissipate." and well there is even a big helper here: same page "Stretching will also aid in lactic acid release from the cell because oxygen reaches the muscle." Well and if it is not good enough over all here the final solution: Page 32 "The body deals with lactic acid in several ways. Removing the acid through the bloodstream to be excreted through sweat and urine.. Reconverting it to glucose and glycogen to be used for energy. Converting small amounts to protein. Converting it to CO2 and H2O which can be used in aerobic activity, or excreted." Well and than we have the activities of efficiency in the pulmonary system. Page 42 " With exercise the alveoli become more efficient at doing their job , allowing greater transport of oxygen in and wastes out." Hmm well at least there is the overall effect of exercise. The energy boost/second wind. " page 45 Where we learn , that there is a chemical endorphin, which is released from many parts of the brain. and again with the second wind we have an additional way of "removal of lactic acid that may have accumulated earlier in the exercise, because of delayed blood flow to the muscles." Wow I always thought Graydon's info was "heavy duty stuff" to comprehend , but nothing against this book hear. Well it may take us some time to pick this up and we should be able to do this. Last page. "Trainers throughout Canada use this manual, including those in the RCMP, and in universities and colleges in BC, Canada and New Zealand. This theory course has been used to teach thousands of people how to be fitness trainers. " Sally Larrington-Brown from Victoria writes: " As a trainer of fitness leaders I have seen many manuals through my years of teaching and I have found the Body Blueprint manual to be the most comprehensive, entertaining and educational." Well some possible advice to my daughter: It is for sure educational in Andri's word: Education is , if you are able to repeat what you learned. Entertaining , well for some it must be a lot of entertainment. Comprehensive: That's for sure. I am surprised how easy it is to "solve" on 200 pages all the fitness questions easy and clear with a very direct and fixed solution. Starting by 220 - age , to the " sweating out of lactic acid , to a clear program of stretching , and as the dessert of it all a clear understanding of Stress .( To bad Hans Selye could not get that far. ) So please help, my Family is full of fitness educated Kids , who more and more think their dad must be nuts. Over 30 years of searching for some answers, he is still nowhere, and we learn this all in 2 month. Anybody out there , help a poor dad to improve his image. Cheers to all other poor dad's. | ||
| Juerg New member Username: Juerg Post Number: 91 Registered: 04-2006 |
So a new year and as usual new ideas, some better than others. An intriguing combination could be the whole hypothesis on the "shuttle" ideas. What started out with an introduction by Brooks (1985) simply as a lactate shuttle is now evolved in a whole new directions of shuttles. Here are just some to start in this directions: 1. lactate shuttle or now better known as the cell-to-cell shuttle. 2. The Astrocyte-Neuron lactate shuttle 3. Lactate_Alanine Shuttle 4. Peroxisomal Lactate Shuttle 5. Spermatogenic Lactate Shuttles Plus the 2 interesting fields of: Lactate in Injury, Sepsis and hemorrhage, as well as the Glucose Paradox of Cerebral Ischemia. So there is a lot out there , which may be worth while to check out , and see , how we can implement certain ideas or possibilities in our training philosophy and try to move the more theoretical points down to "earth" so we as people on the street can benefit from them as well. So let's see hwat 2007 has in the bag for us. Juerg |