Wednesday, January 27, 2010

So lactic acid is good now?

I don't even know where I heard it first, but I always thought that burning sensation in your muscles from anaerobic activity that inevitably forces you to quit was "lactic acid building up in your muscles". After reading this very informative article from Matt Fitzgerald on, it turns out I was way wrong. In fact:

1) Lactate is actually a direct and indirect fuel to the muscles.

2) It DELAYS fatigue in muscles, not cause it.

3) One shouldn't minimize lactate buildup during training, one should increase it.

Boy, did I have that one wrong! Matt writes a great article, historically walking through the scientific understanding of lactate, and even offers some walkaway (or sprint-away) tips for training. Be sure to give it a read.



  1. Hey Scott! Love your blog site. What a long list of events for 2010! Just ran the southern cali half marathon last month. Weather was awesome unlike Eugene's. Keep it up.

  2. that burning feeling is actually Hydrogen build up which cannot be processed quickly enough to keep up with the demand... because why???? That's right, you are not able to produce enough lactate... this is called lactate threshold:)

  3. If it delays do you get more of it? My biggest problem is muscle fatigue whether its running, working out, etc.

  4. Hmm, as a fan of this informative blog, I have to add my two cents.

    I think the article is interesting but its main conclusion is that we should train more frequently above the lactate threshold (LT), not try to build up more lactate.

    Our lactate levels go from 0.5 to 1 (I forget the units) in arterial blood; a little higher in venous. If a human's heart is stopped for 60 seconds, trust me, you will see some insanely high lactate levels. In severely ill ICU patients, you will see up to 15. This is because they are not able to bring oxygen to their tissues.

    A high lactate level in the hospital is bad, absolutely no doubt about it.

    As the article points out, it was once believed that lactate in itself was dangerous. It might be in sick patients (lactic acidosis can be dangerous, especially in patients on certain meds), but not in healthy runners.

    The article points out that lactate has beneficial effects on muscle function. This is an old truism in the body. Anemia, fever and acidosis, which are all markers of disease are in themselves actually helpful in oxygen delivery.

    However, even though lactate in itself is not dangerous, it is a marker of anaerobic metabolism, just as the LT is an approximate point of where you go from aerobic to anaerobic. If you had a lactate reader on your Garmin, you would see a break point at a certain heart rate, after which the lactate would start rising.

  5. Thank you guys for your clarification comments! Makes the blog entry much better. I've been getting a lot of click-through from Google...good thing those of you who know more about the subject are willing to comment!


  6. I don't know lactic acid - but I think that barefoot gal in the bikini ran by me at mile 80 last summer. My crew thought I was having a stellar finish but I was just chasing a hallucination...

  7. So what next? Lactate threshold monitors? People are always resistant to new ideas.

    Try it for yourself. Add a couple more high intensity workouts and see if you notice results.


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