How Lactate & Metabolism Influence Performance

1. Dr. Andy Galpin

   The science and practice of enhancing human performance for sport, play, and life. Welcome to Perform. Hello, friends. I'm Dr. Andy Galpin. I'm a professor of kinesiology in the Center for Sport Performance at Cal State Fullerton. In today's show, we're going to be talking about lactate, or how many of you probably think of it, lactic acid. Now, I know when I say those words, you immediately start thinking about things like exercise and muscle and fatigue, soreness, and reducing exercise performance, and that all is true, kind of. In fact, as we're going to lay out, the overwhelming perceptions and thoughts about what lactate or lactic acid really are and what they're doing are massively false. In fact, I'll spill the beans right now. Lactate is in no form or fashion cause of your muscle fatigue. It actually does quite the opposite. It preserves muscle performance. We'll get into all that stuff later.

2. Dr. Andy Galpin

   In fact, I actually think it highlights why I wanted to have this conversation or do this episode is because it's high time we start really understanding what lactate truly is and how it's functioning in our body. It has classically been thought of as this waste product, something that you don't want around, something that you want to avoid at all costs or manage or mitigate whenever possible. And the reality of it is, it has a number of widespread benefits across your entire physiological landscape. Let me give you a couple examples of what I'm talking about. Lactate is known to stimulate a molecule called PGC1-alpha. This is involved in any metabolically active tissue in any part of your body, and it is directly responsible for mitochondrial biogenesis. This is another way of saying, by increasing and utilizing more lactate, you're going to be increasing and making more mitochondria. This is a known response, and this is obviously a positive thing for overall health and performance.

3. Dr. Andy Galpin

   But it even goes beyond that. Let me give you a couple of other examples you may not realize. For example, did you know lactate targets Leydig cells, which are responsible, of course, for testosterone in your body? It has a number of other benefits, such as BDNF, so brain-derived neurotrophic factor. This works directly on the hippocampus to stimulate neurogenesis, so the growing of new neurons, particularly in your brain. Similar idea with a molecule called VEGF, which is responsible for endothelial cells and then therefore promoting angiogenesis, so the growing of new vasculature throughout your entire body. Ghrelin, which is associated with hunger, so lactate actually acts directly on the hypothalamus to regulate ghrelin, and one of the major benefits here is suppression of appetite. I don't need to explain a lot to you there, but very few people can do a high-intensity exercise bout where they generate a lot of lactate and then feel extremely hungry immediately afterwards.

4. Dr. Andy Galpin

   So appetite suppression with high lactate is a pretty easy one to imagine. I'm going to go even further, though, because there's so many more things lactate's doing. Whether we're talking about the liver and the kidneys and increasing what's called gluconeogenesis. So as you'll see later in our conversation, the primary place that we're getting the molecule or precursors for gluconeogenesis is lactate. Another benefit is its ability to act on osteoclasts and therefore play a role in bone remodeling. Now, I could go on and on here, and we're not quite done yet because I want to give you a handful of ones. I'm going to rapid-fire these ones. But lactate, again, has been highly associated with positive adaptations across your brain. It's heavily involved in memory and learning, heart health, dehydration. In fact, any of you that have ever used a Ringer solution, I know exactly what I'm talking about there.

5. Dr. Andy Galpin

   Cancer, sepsis, insulin regulation, traumatic brain injuries, wound healing, post-surgery recovery, arthritis, inflammation, gut microbiome health, and then finally, overall metabolic flexibility. My guess is you had no idea that many things were happening in response to lactate. So in order to understand all these things, what I would love to do is spend a little time today walking you through exactly what lactate really is, how it's created, how it's managed, what role it's truly playing in your overall physiology. And then, of course, at the end, we will do our three I's, which is investigation. How do I measure this stuff? What should I be paying attention to? Two, interpret. How do I know if I'm good, bad, great, terrible, or world record? And then three, intervene. How do I improve my body's ability to produce and clear lactate so that it can perform at its highest level regardless of the task I'm asking my body to perform?

6. Dr. Andy Galpin

   To get us started on this journey, we're going to go all the way back to the beginning when we initially discovered and began to understand the role of lactate in really all of biology, but specifically in human exercise physiology. The story really starts in 1708 when Scheele found lactate in sour milk. Now, the term he gave it actually roughly translates, I think, into milk acid, but it really persisted in this idea of just general food space until nearly 30 years later in 1808 when a scientist, Berzelius, and I have tried to pronounce this at least 200 times. But Berzelius really, and this is a classic story in all exercise physiology cycles, he found that concentrations of lactate were much higher in hunted stags, so a deer-like creature in Europe. And so it's very clear at this point that lactate is somehow associated with elevated stress or exercise, and we didn't really know much past that, but it seemed to be in all of physiology at this point.

7. Dr. Andy Galpin

   So we had now crossed over from things like food elements and bacteria into now human physiology. So that was really a big step up in terms of our understanding of the relative importance of it for living creatures. Now, Berzelius went on to do a whole bunch of other stuff in this field, and in fact, he was directly responsible for the name that you all probably recognize as a catalyst. By studying lactate and trying to figure out what's going on, he really came up with this idea that he called ferments. Now, that sounds familiar because it is where we got fermentation from. In fact, you may be starting to make a connection in your brain, which we'll do a little bit more directly later, that really lactate and fermentation are almost one and the same. In a human exercising muscle, we call it anaerobic glycolysis and lactate production. In food elements and in the food industry, we call it fermentation.

8. Dr. Andy Galpin

   Not exactly the same, but very, very close, and I'll maybe explain that a little bit more later. We haven't really moved into the realm yet of exercise physiology. There was no real understanding that this was happening as a byproduct of muscular contractions or anything like that at this time. We were still at the level of understanding what happens when carbohydrates are used with and without oxygen. So in fact, we can be more direct here. When we break down carbohydrates for a fuel source, that's fermentation. You do the same thing with protein, we call that thing putrefaction. Same thing happens with fat, and you call it rancidification. And so matter of fact, you may have never made that connection before, but you ferment carbohydrates, fats go rancid, and proteins are putrefied. So at this point in the story, we're kind of into the mid-1800s. In fact, in 1843, Scheurer was the first to find lactate in the blood.

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