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  1. #1
    DLd
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    The Lactic Acid Myth - Has anyone seen this?

    Here's a piece from the article.

    The idea of the cool-down seems to have originated with a popular theory ó now known to be wrong ó that muscles become sore after exercise because they accumulate lactic acid. In fact, lactic acid is a fuel. Itís good to generate lactic acid, itís a normal part of exercise, and it has nothing to do with muscle soreness. But the lactic acid theory led to the notion that by slowly reducing the intensity of your workout you can give lactic acid a chance to dissipate.

    Found here: http://www.nytimes.com/2009/10/15/he...?_r=1&emc=eta1

    This is the first time I've seen this. All of the current training literature I read, be it Bike Magazine, or Men's Fitness, or books, still seem to talk about lactic acid buildup. I was just wondering if anyone else was familiar with this. A quick search of the posts with lactic acid didn't bring up anything to suggest any drop in the lactic acid theory.

    Thoughts?
    "Great things are not accomplished by those who yield to trends and fads and popular opinion."-Jack Kerouac

  2. #2
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    Yes, lactic acid can be "recycled" as a fuel. The purpose of a cooldown is to allow your heart rate, BP, and bloodflow to return to normal. It doesn't really have anything to do with muscle soreness, which is caused by microscopic muscle damage and the inflammation that follows.
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    I'm agreeing with Andrea here. Higher concentrations of lactic acid clear very quickly once you reduce your intensity. The cool down is a smart training tool for other reasons. You slowly return your "systems" to normal and you keep some good, oxygenated blood flowing to your legs to start repairing the microscopic muscle damage and inflammation following hard efforts. It is similar to an "easy spin" on a recovery day in that in can speed recovery.

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    Lactic acid is an anaerobic (no oxygen) product of the muscle when the muscle is pushed.
    Also the muscle burn as youre working could partly be attributed to lactic acid, but then goes away in a few minutes as the blood carries it away.
    Next day muscle soreness is from the breakdown of the muscle due to activity.
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    I think the implications of these studies gets misinterpreted - no one questions that muscle acidosis results results from intense exercise. The open issue is whether this is due to lactic acid accumulation, other acids, or other mechanisms of acidification. The question of underlying substrate doesn't much matter for practices athletes do (unless you're taking supplements that are supposed to target particular substrates). E.G., whether active vs. passive recovery is more effective doesn't depend on underlying substrates.



    Boning D, Maasen N. Point: Lactic acid is the only physicochemical contributor to the acidosis of exercise. J Appl Physiol; doi:10.1152/japplphysiol.00162.2008.[Free Full Text]

    Lindinger MI, Heigenhauser GJF. Counterpoint: Lactic acid is not the only physicochemical contributor to the acidosis of exercise. J Appl Physiol; doi: 10.1152/japplphysiol.00162.2008a.[Free Full Text]

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    The problem is that lactic acid over the years has been considered a waste product, or something bad in our system, but lactate is used as an energy source for some tissues such as Red blood cells and cardiac muscle and it is a valuavle source of energy that is store in our body.
    Even at rest or while doing an easy -moderate exercise, some lactic acid still being formed, but it does not accumulated in "Large" amounts in the blood since the rate of production equals to the rate of removal.
    Now, when we are increasing the intense of the workout, in which there is a a bigger demand of oxygen supply,all the H+ cannot be proccessed forming lactic acid and NAD+ . Once we reduce the intensity of the workout, or cessation of exercise, lactic acid releases H+ that are eventually oxidized. Lactic acid is converted to pyruvic acid and "Used" as an energy source.

    Well-trained athlete will have blood lactate value greater than untrained athletes under similar conditions. and Ofcourse there are specific training or workouts that can improve the ability to produce lactate.....

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    oh and the idea if cool down is to allow a faster buffering of the accumulated hydrogen ions in the muscle through mainting blood flow at an elevated rate and maintaining elevated ventilation (the promary method os removing acid from the body) it has been studied that active recovery at an intensity of about 40% of VO2max lowered lactate levels quicker than simply sitting at res, thats why instead of havinf a day off I rather have an easy zone 1 recovery ride.... when I mean easy its easy...

  8. #8
    DLd
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    Quote Originally Posted by Gatorback
    I'm agreeing with Andrea here. Higher concentrations of lactic acid clear very quickly once you reduce your intensity. The cool down is a smart training tool for other reasons. You slowly return your "systems" to normal and you keep some good, oxygenated blood flowing to your legs to start repairing the microscopic muscle damage and inflammation following hard efforts. It is similar to an "easy spin" on a recovery day in that in can speed recovery.
    Oh, I don't disagree on the cooldown aspect, for the simple reason that if I stop suddenly from a hard effort my muscles seem to stiffen up more than if I maintain an easy effort for a few minutes before I stop. I was more interested in the lactic acid part of the article. I just posted the link to cite my source. The overall article seemed to be written with the bias of the author trying to justify his own lack of a cooldown and use his position as a reporter to make his neighbor look like a dumbass. In fact, the gist I get from the article is that the best thing to do would be to finish the ride with a hard effort, and then immediately lay down. This way you don't waste your lactic acid doing a cooldown, and you also don't risk getting dizzy and falling down from the blood pooling in your legs. I'm not actually going to do that though...
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    Quote Originally Posted by EvilGringo
    Lactic acid is an anaerobic (no oxygen) product of the muscle when the muscle is pushed.
    Also the muscle burn as youre working could partly be attributed to lactic acid, but then goes away in a few minutes as the blood carries it away.
    Next day muscle soreness is from the breakdown of the muscle due to activity.
    Lactic acid is partially oxygenated, kinda like partial burning diesel fuel to get more power, you end up with black smoke....

    Lactic acid is then fully oxygenated when the body has enough oxygen and time to complete the job....

    Best cool down for me....

    Go stand in a nice cold river for 5 minutes or so, the blood flow to the legs reduces very quickly, the veins contract and the blood flows from the legs into the core....

    Some of the toxins flow with that blood and are consumed by the body and liver....

    When you get out of the cold water the blood flows back in and the legs feel refreshed...

    Lots of atheletes doing this now a days.

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    The icing thing eh. Cooldown, icing, stretching, they all seem to have bloodflow in common. My personal (unscientific) theory with stretching is that is helps get blood into connective tissues that don't get much bloodflow ordinarily - tendons and such, which mainly get blood through osmosis and not blood vessels.

    According to some random article I found on the internet, the body's response to cold in the extremities is to dilate at least the surface blood vessels at first (red flushed skin), and then after prolonged cold to alternate periods of dilation and restriction, and then finally to restrict bloodflow, sacrificing the extremities to maintain core warmth. So according to that it sounds like soaking the legs in cold water may increase bloodflow to them in the short term.

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    Perhaps it depends on the amount of cold....

    Stepping thigh deep into a cold river is enough to get the hyperthermic response happening, blood flow is reduced to the cold portions of the body....

    Pretty clear when I step out the old legs are skinny white chicken legs, no matter how tanned I am.

  12. #12
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    This thread makes me sad in my happy place. I don't have time to address all of the misinformation here or circulating around the web about the role of lactate in metabolism, but I would highly recommend that anyone interested in the topic start by reading a general animal physiology text book. Of the posts above, Sebastian's is the most correct (though I don't recommend fueling cardiocytes with lactate ). Most tissues produce lactate as an anaerobic end product pretty much all the time. During intense exercise, oxygen limitation leads to an increased accumulation of lactate. Anaerobic metabolism produces less ATP (the energy currency of cells), but in the absence of oxygen, this is better than nothing. Once that exercise is over, lactate is converted back to pyruvate which is then used for regular aerobic metabolism, with some net loss of ATP. As mentioned, muscle soreness is typically caused by inflammatory responses as a result of cell damage.

    Whew, that isn't really the whole story, but hopefully clears some things up.
    Last edited by transient; 10-23-2009 at 12:46 PM.
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    Quote Originally Posted by jeffscott
    Perhaps it depends on the amount of cold....

    Stepping thigh deep into a cold river is enough to get the hyperthermic response happening, blood flow is reduced to the cold portions of the body....

    Pretty clear when I step out the old legs are skinny white chicken legs, no matter how tanned I am.
    Cold = reduced inflammatory response = less soreness
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  14. #14
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    Quote Originally Posted by sebastian21
    oh and the idea if cool down is to allow a faster buffering of the accumulated hydrogen ions in the muscle through mainting blood flow at an elevated rate and maintaining elevated ventilation (the promary method os removing acid from the body) it has been studied that active recovery at an intensity of about 40% of VO2max lowered lactate levels quicker than simply sitting at res, thats why instead of havinf a day off I rather have an easy zone 1 recovery ride.... when I mean easy its easy...
    actually there's some evidence that active recovery is no more effective than passive recovery. Considering that many people ride too hard on so-called recovery rides and the value of a psychological break from the bike, taking a day off might be better for a lot of people.

    http://conditioningresearch.blogspot...-study-on.html

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    Quote Originally Posted by stevesbike
    actually there's some evidence that active recovery is no more effective than passive recovery. Considering that many people ride too hard on so-called recovery rides and the value of a psychological break from the bike, taking a day off might be better for a lot of people.

    http://conditioningresearch.blogspot...-study-on.html

    It all depends on the level of fitness....and also how serious are you about your training and racing goals, level.. I mean there are many factors, for some riders a Day off will pay off better than to have an easy recovery ride....

  17. #17
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    What sort of field would you get into for learning this type of stuff? Sports Medicine or something?

  18. #18
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    Quote Originally Posted by CanOnlyRide
    What sort of field would you get into for learning this type of stuff? Sports Medicine or something?
    Sport Science mainly.....

  19. #19
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    i was told in my sports med class that lactic acid was a fuel and the soreness was from the fact that every time you move a muscle you create tiny tears in the muscle fibers.

    and that you need to eat a good meal right efter a workout, cause otherwise all you did is make yourself sore

  20. #20
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    Quote Originally Posted by CanOnlyRide
    What sort of field would you get into for learning this type of stuff? Sports Medicine or something?
    If you wanted to know the real story, PhD in organismal physiology

    Pretty much anything else is going to be warmed over lies. Even most peer reviewed exercise or sports medicine is considered bunk by the broader scientific community. If the author has M.D. behind their name, there is a good chance the study is crap. [/Rant]
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  21. #21
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    Quote Originally Posted by DLd
    Here's a piece from the article.

    The idea of the cool-down seems to have originated with a popular theory ó now known to be wrong ó that muscles become sore after exercise because they accumulate lactic acid. In fact, lactic acid is a fuel. Itís good to generate lactic acid, itís a normal part of exercise, and it has nothing to do with muscle soreness. But the lactic acid theory led to the notion that by slowly reducing the intensity of your workout you can give lactic acid a chance to dissipate.

    Found here: http://www.nytimes.com/2009/10/15/he...?_r=1&emc=eta1

    This is the first time I've seen this. All of the current training literature I read, be it Bike Magazine, or Men's Fitness, or books, still seem to talk about lactic acid buildup. I was just wondering if anyone else was familiar with this. A quick search of the posts with lactic acid didn't bring up anything to suggest any drop in the lactic acid theory.

    Thoughts?
    A quick search revealed this: Lactic Acid is actually good for you!

  22. #22
    Dirty South Underdog
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    Quote Originally Posted by CanOnlyRide
    What sort of field would you get into for learning this type of stuff? Sports Medicine or something?
    My background is an MS in Health and Sport Science.
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  23. #23
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    Good job!

    Quote Originally Posted by jeffscott
    Lactic acid is partially oxygenated, kinda like partial burning diesel fuel to get more power, you end up with black smoke....

    Lactic acid is then fully oxygenated when the body has enough oxygen and time to complete the job....

    Best cool down for me....

    Go stand in a nice cold river for 5 minutes or so, the blood flow to the legs reduces very quickly, the veins contract and the blood flows from the legs into the core....

    Some of the toxins flow with that blood and are consumed by the body and liver....

    When you get out of the cold water the blood flows back in and the legs feel refreshed...

    Lots of atheletes doing this now a days.
    Yes, this does seem to work. It took about 20 years to become mainstream (no pun).

  24. #24
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    Quote Originally Posted by stevesbike
    no one questions that muscle acidosis results results from intense exercise. The open issue is whether this is due to lactic acid accumulation, other acids, or other mechanisms of acidification.

    Actually they do.
    This study shows that intramuscular pH only drops seconds after exercise, but is very stable during exhaustive exercise.
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    I guess my question is that now that we know that lactic acid is an energy mechanism and not a waste product, does that make any difference in how I train? Is lactate threshold important anymore?

    It seems to me that if you're looking for a 'marker' of fatigue to use for training, that lactate threshold would still be as valid as ever. There's no reason not to still do base training at a certain percentage of lactate threshold, do intervals at a certain percentage over the threshold, etc.

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