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Lactic Acid Debunked: ALL Spinning® and Indoor Cycling Instructors Please Read!

By Jennifer Sage On February 15, 2014 Under exercise science
Team Sky Froome of Britain sprints on the finish line ahead of BMC Racing Team Evans of Australia and Team Sky Wiggins of Britain at the end of the seventh stage of the 99th Tour de France cycling race between Tomblaine and La Planche des Belles Filles

Photo credit: Steephill.tv/Reuters

SCIENCE WARNING! This post is going to refer to several articles that get into some serious exercise physiology that is extremely relevant to what happens in a Spinning® or any other indoor cycling class. As a result, I truly HOPE that you, as an indoor cycling instructor (and perhaps even those who are simply students) are eager to read it with great interest. Our industry needs more instructors who are passionate about how the body works, or at the very least, interested in making sure they know the difference between lactic acid and lactate, how it’s produced, and what it means in improving (or hindering) fitness.

I don’t care whether you are Spinning® certified, or Schwinn, or Keiser, or have a 5-hour, lesser known certification, YOU NEED TO KNOW THIS, and you need to know it well!

Velo News posted an article in December on the myths of lactic acid and lactate. It is one of the better explanations of how our understanding of lactic acid and lactate have been confused over the years. The author, Trevor Connor, says:

We all remember the gym coach who roared about how you weren’t working until you felt that lactic acid burn. The phrase “lactic acid” is part of our sports lingo. How many times have we heard “gotta clear the lactic acid”? Well, it turns out that the coach was slightly misinformed. More and more, I have endurance athletes asking me the truth about lactic acid: 1) Are lactic acid and lactate different and which one do we have in our bodies? 2) Does lactate have a purpose?

Later in the article, he asks:

Does lactate serve a purpose?

Our misunderstanding about lactate gave it a bad rap. It was believed that lactate was just a nasty waste product that made our legs scream 50 meters from the finish. In reality, lactate serves many important roles. For example, “it is the principle fuel for the heart during vigorous exercise,” Hickey said. And the liver can recycle it, “releasing a brand new glucose molecule as if you’d been drinking a sports drink.”

The reality is that we are constantly producing lactate in our bodies. “There’s a misunderstanding that until you get to threshold you’re not making lactate. That’s not the case,” Hickey said. “You’re making lactate 24/7 all your life.”

The same goes for acid, those hydrogen ions. The reason our blood lactate levels are low most of the time is because our bodies clear and use it as quickly as we produce it. Our lactate threshold is simply the point where our bodies produce both lactate and acid faster than it can clear them. This makes our ability to clear lactate and acid a critical part of sustaining high-end power.

Following that article, Velo News received several challenges to Connor’s article. He answered them beautifully in an article this week called Point/Counterpoint: Lactic Acid Debunked. This article dives in even deeper into the chemical reaction that creates lactate and hydrogen ion (H+). Connor says:

Third and most importantly, at no point in its physiological pathway does lactate function as an acid. Lactate is formed by binding a hydrogen ion to pyruvate inside cells, so as recent research is showing, lactate formation not only doesn’t contribute to acidity but in fact acts as a buffer by binding intracellular protons. Further, the lactate that is pumped into the blood never has a physiologically dissociable hydrogen ion that can contribute to acidosis. A hydrogen ion does leave the cell with lactate, but it is believed that there again, the lactate is helping to maintain intracellular pH by acting as a co-transporter. Reberg et al. concluded that the hydrogen ion was not produced by lactic acidosis but by ATP hydrolysis. They go on to say, “there is no biochemical support for lactate production causing acidosis. Lactate production retards, not causes, acidosis.”

It may take a few times reading it to fully grasp what he is saying, but I do hope it furthers your own knowledge of why lactic acid does not exist in the body, and why the term should disappear from your vocabulary when referring to anaerobic glycolysis.

This discrepancy in understanding of lactic acid and lactate, and what causes the burning sensation we feel when we are above our lactate threshold, has been something I’ve been trying to improve in this industry for quite a while. The more instructors misuse the terms, the longer it will take for these myths to disappear. Back in September of 2012, I wrote a post called “Spinning and Indoor Cycling Instructors, It’s Time to Get the Lactate Thing Right!” You may want to add the three articles referenced in that post to your reading list.

I wrote another article called Learn More About Lactate Threshold: My Goal for the Industry Since 2007. 

And finally, my very favorite analogy of the lactate threshold, as told through Lucille Ball!

4 Comments Add yours

  1. Vickie jarosz
    February 16, 2014
    12:45 am #comment-1

    Dr. Lenny Kravitz educated me about this many tears ago. Difficult to get the mainstream instructors to switch their thinking.

  2. Jennifer Sage
    February 16, 2014
    5:56 pm #comment-2

    It is difficult Vickie, isn’t it?

  3. Elsie
    February 20, 2014
    7:06 pm #comment-3

    What a great article and a different way of thinking about breathing while exercising. I feel so enriched with this information. Thank you – Elsie

  4. Lisa
    February 22, 2014
    1:17 pm #comment-4

    I think we need a quick, snappy term. Asking riders to clear those “hydrogen ions” just doesn’t sound as cool, or urgent as warning against “lactic acid” build up!

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