[Transcript] – Performance Nutrition, Sweat Sodium And The Secret Hydration Formula Of The World’s Top Endurance Athletes.

Affiliate Disclosure


Podcast from:  https://bengreenfieldfitness.com/podcast/supplements-podcasts/allen-lim-nutrition/

[00:00] Introduction/Harrys/Inner Circle

[03:56] About Dr. Allen Lim

[10:37] Osmosis& Osmotic Pressure

[17:22] On Diluting Sports Drinks

[20:08] Burning& Regaining Body Substances

[35:13] Using Sushi Rice

[42:37] Performing in Low Carb States

[45:55] Using Skratch to Maintain Hydration

[50:23] On Sweating in the Body

[55:20] Losing Sodium in the Body

[59:21] Skratch Hyperhydration Mix

[1:03:10] Interview at the Team Timex Camp

[1:14:56] End of the Podcast

Ben:  Hey, Ben Greenfield here.  Two quick things before we jump into today's nutrition nerdiness will Allen Lim.  The first is that this podcast is brought to you by Harry's. Now Harry's is a company that makes their own shaving blades, but these are actually not any old, disposable shaving blade that leaves your face raw and cut which nobody likes. They're high quality, high performing German blades crafted by shaving experts.  I'm not quite sure how one becomes a shaving expert, but I also don't care.  All I know is that these blades actually work, and they're about half the price of the other big, branded blades.  I won't use any names, but I can tell you that one rhymes with Hillete.  Anyways, you can go to harrys.com and enter coupon code “Ben” to get five dollars off anything from Harry's, including their starter set which is a razor, some moisturizing shaved cream that doesn't have anything in it.  That's going to decrease your testosterone or introduce a bunch of phthalates or parabens into your skin, and also three razor blades.  So that's called their starter set, and you can check that out or you can just take a razor if you want to take the minimalist route.  Either way, you get five-dollar savings no matter what you choose when you go to harrys.com, and you enter coupon code “Ben”.

The other thing that I wanted to make you aware of is that I personally log every single day, every workout I do.  From my strange twists on yoga routines to my gallivanting about doing obstacle course workouts to the more standard traditional workouts that I do in the gym.  Pretty much everything I do, you can follow if you just want your workout outsourced, and I log all of that inside the Ben Greenfield Fitness Inner Circle along with photos of my food, recipes etcetera, and you can check that out at bengreenfieldfitness.com/innercircle.  So now you can sit back or keep swimming, cycling, running, lifting weights, meditating or whatever else it is that you're doing, and get ready for today's nutrition nerdiness with Dr. Allen Lim.

In this episode of The Ben Greenfield Fitness Podcast:

“I think that we for whatever reason, always think about performance and endurance sports about being getting adequate calories.  But the reality is that in the same way that we can survive for weeks without food but only days without water, performance is very much the same.”  “If we can find a sugar ratio or a ratio of glucose that does matches the ratio of glucose-fructose transporters in the small intestine.  Essentially what we get is we get two lanes of traffic.”  “There's some good literature out there that shows that chronic sodium depletion over time could lead to science of over breaching and over training.”

Ben:  Hey folks, it's Ben Greenfield here, and I wrote an article way back over at bengreenfieldfitness.com called “The Real Truth About What To Eat Before, During And After Your Workouts & Races”, and in that article, I mentioned a guy named Dr. Allen Lim, and I specifically gave a shout out to the recipes that he invented when he was director of sports science for the Garmin and the RadioShack professional cycling teams.  And in that article, I was talking about recipes like chocolate and sea salt, sticky bites, blueberry and chocolate coconut rice cakes and things like crispy rice omelets, and I know that you cannot argue that those don't sound tasty, and yes, we will be in the interview today talking a little bit about how those type of things jive with the whole high-fat, low-carb diet for you high-fat zealots out there.

But anyways a few weeks ago, I attended my Team Timex Triathlon camp where Allen was there conducting sweat sodium analyses, and we had a chance to chat a little bit during my sweat sodium analysis, and I'm going to include the audio of that chat as a bonus after today's interview, but I had so many other things that I wanted to talk to you, Allen, about everything from the ingredients that are used in sports nutrition compounds these days, to whether electrolyte intake during exercise is useless or beneficial to fat utilization during exercise and ketosis that I'd thought he'd be a great guest to get on the show.  And if you don't know much about Allen Lim, we'll be sharing a little bit more of his story when we jump into our conversation, but he's basically an exercise physiologist, he's a cycling coach, he's the founder of something called Skratch Labs.  He's the guy that developed the method of testing for biological makers of performance enhancing drugs that led to professional cycling's biological passport.  He's worked with dozens of top American cyclists.  He's also worked with a bunch of professional triathletes.  He's worked with guys like Lance Armstrong and George Bush, and he’s also the author of a couple of books, “The Feed Zone Cookbook” and “Feed Zone Portable”, two books that I personally own and use.

So we're going to be jumping in and chatting with Allen.  If you want to access any of the resources that we talk about today, just go to bengreenfieldfitness.com/skratch.  That's Skratch with a K, bengreenfieldfitness.com/skratch.  So Allen, thanks for coming on, man.

Dr. Allen:  Thanks for having me.

Ben:  Hey, I'm curious how exactly you got into all this, 'cause at Timex camp, you were sharing with me, I believe about how you are Filipino-Chinese or something like that.
Dr. Allen:  Yeah, all my parts are from China, but I was made in the Philippines and programmed here in the United States of America.  So we immigrated here when I was just a baby pretty much and grew up in Los Angeles, fell in love with cycling, fell in love with human performance at a really young age and set out to make it my career ever since.

Ben:  Nice, how did you get involved with professional cycling as far as Team RadioShack and Garmin working with Lance Armstrong?

Dr. Allen:  Yeah, well I had started out racing bicycles in Southern California on a little team called the Montrose Cycling Team.  Grew up with a great group of riders from my cousin, my brother, guys like Holden Morris and Tony Cruz and Freddy Rodriguez, and we stormed all over the place in Southern California, race bicycles, and by the time it was time to go to college, I realized that I didn't really have it to be a professional cyclist. So I started studying exercise science at the University of California, Davis.  My senior year at Davis, I started coaching the collegiate team there, helping out the women's team, and we had a lot of success.  It was a ton of fun, and I realized that not only did I love the sport science, but I also loved the coaching aspect.  I then left Davis, went to the University of Colorado at Boulder.  I started coaching at Sea, Boulder, got my master's degree in exercise physiology under the direction of Dr William Burns, then I got this little gig coaching as a resident coach at the Olympic training center, and it just continued.

After about a year or so that I went on to do my PhD in the integrated physiology department at Sea, Boulder, again under the direction of Dr. Bill Burns.  I worked in his applied exercise science laboratory, and a big part of my project was trying to understand how portable power meters could be used to better understand training load.  At the time, I had been working with these engineers with a product called the Power Tap, and eventually the Power Tap was sold to the CERA Cycling Group, and that's pretty helpful in my education, the adultment of the Power Tap.  I became one of the early guys using portable power meters to try to understand training load in professional cycling.

By the time that I was finished with my PhD, my dad had passed away, and I wanted to take some time to just be with my mom and human being in mourning.  I found myself without a job, doing pretty much nothing, and it was at that time that Power Tap came to me and said, “Hey, you want to go into the pro-touring, help some of the riders we sponsored, etcetera.”  So I came into the sport of professional cycling around 2005, and it was crazy.  It was this dream come true for me.  On one hand being in events like the Tour de France.  On the other hand, it was so much work, and the sport was in so much chaos.  It was kind of 99-1.  It was 99% bullshit, 1% pure magic.  I ended up fearing away to try to live for the magic and try to make things better in the sport, and that led me to conversations with Jonathan Vaughters and what he was doing with his young TIA craft team, and we decided that it'd be great to try to start from scratch with this sport of cycling, give this new young generation, an American cyclist a chance to ride clean and to really prosper in a very American way, and so we started working with the guys at UCLA , and we started doing our version of the bio passport, groom these young kids into the Garmin Professional Cycling Team, and then I did a few years there.  Then eventually went to RadioShack for two more years, and then retired from the sport and then started Skratch Labs.  So it's been a crazy, wild ride all over the place.

Ben:  Yeah, now speaking of Skratch Labs, I think one of the first places that I saw you, Allen, was on YouTube, and you were doing a video about eggs and hydration.  I don't know if you recall the details of that video, but if so can you share the idea behind that video 'cause it's kind of a perfect way to express your unique ideas when it comes to hydration science?

Dr. Allen:  Yeah, you know what we found when I was working with Garmin was that if the sports drink was too sugary, if it was too sweet, if it had too many ingredients, in fact it was at a higher concentration than blood, and if riders drank too much of it in one time, they would get gastrointestinal distress.  They would feel bloated.  The water when it passed through their small intestine at a fast enough rate, and in worst case scenarios, they would end up in diarrhea.  And I'm sure for many endurance athletes, they'd have experienced this “gut rot”, right?

Ben:  Yeah, what kind of concentration are we talking about, in terms of percentages?

Dr. Allen:  You know you can get gut rot as low as 6%, depending upon how many other ingredients are in a solution.

Ben:  And to put that into context for folks, what would be, let's say Gatorade or Powerade or something like that?  What's the concentration of something like that?

Dr. Allen:  Yeah, those drinks are probably in the 6% range, that's six grams of carbohydrate for every hundred mills of fluid.  So six over a hundred, that's your 6%, and that's an easy way to talk about how sweet or how much sugar a drink has.  But what people I think didn't really realize was that it's the net molecular concentration that affects the movement of water across the small intestine.  That net molecular concentration can be measured in units of milliosmoles or in osmolarity.  So we often talk about the molecular concentration as the osmolarity or as the osmotic pressure of a solution, and that osmotic pressure is not just the sugar, but it's also the coloring agents. It's also the emulsifier, it's also the flavoring agents, and it’s also all of the electrolytes that you have in that drink.  And so if you only have so much room to pack a bus, you want to hopefully carry useful cargo, human beings.  But if you get on that bus with a bunch of goats and chickens, you tend to screw yourself, and that was the problem with a lot of drinks.  If you look at the ingredient list and you compare one drink to another, they may all look the same in terms of say their carbohydrate, your electrolyte concentration, but if one drink has more of these excess food additives, you're going to have a higher osmotic pressure in that drink than one that is simpler.

Ben:  And when you have a high osmotic pressure, what happens in the gut?

Dr. Allen:  Well it depends.  The egg video that I did was a demonstration of something called osmosis.  It's a demonstration of how water moves across what's called a semi-permeable membrane.  A semi-permeable membrane is a membrane that is selective to certain ions.  So water can pass freely but others, other molecules or ions can't.  Let's say you have a barrier, right?  And you have a solution on one side and you have a solution on the other side.  A perfect example of that is the human body.  You have this membrane or this barrier called your small intestine or your gut, and in one side is blood, and that has an osmotic pressure of about 280.  On the other side is whatever you might eat and drink, and if the osmotic pressure on the other side is greater than 280, water likes to move from an area of lower pressure to higher pressure or lower concentration to higher concentration.

So if you drink something that has a higher osmolarity, the osmosis water will tend to flow into your gut, not into your body.  Now the one caveat is that the semi-permeable membrane, they're selective to certain ions.

Ben:  And water, when you say it's flowing into your gut, where is water flowing into your gut from?

Dr. Allen:  From your body, from inside the body.  You know the human body is interesting.  When we think about the gastrointestinal tract, I think that people don't realize that when you put something in your mouth, you're not actually putting it inside your body.  Your GI tract from your mouth to your butt is continuous with the outside world.  You do receive in those little sippy things that you hold in your hand and it's hard to hold, they're filled with water?  The inside of our GI tract is like the inside of that tube, and what happens is when we eat something, food stops in water.  They sit in our intestinal movement, and they're two paths for that stuff.  Either it can be absorbed into the body, into the bloodstream, or it could pass through your GI tract, out your butt, and if this water from inside your body is spilling into your intestinal lumen because what you have just consumed is highly concentrated, that can ultimately lead to diarrhea.

Ben:  Gotcha.  So you're got a high osmotic pressure and solutions that are too concentrated, whether it be from the carbohydrates that are present in them or emulsifiers, fillers, etcetera, and that was the problem that you were encountering when you were working with these professional cycling teams.

Dr. Allen:  That's essentially right, yeah.  One other thing to consider is that when you talk about the things that you might have in your food or in your drink, there's this issue of tonicity, and tonicity refers to the non-penetrating molecules, meaning the molecules that don't have a way to get across your gut.  If you have molecules that are easily transported, say glucose or fructose or sodium, as those molecules get physically transported across the gut, they lessen the osmotic pressure of the solution that you just drink, and water will tend to follow.  So water can enter into the body in basically two ways.  Either through simple osmosis or it can pull across once other molecules are transported.  That changes the osmotic pressure.  In addition, if you pull across some sodium and some glucose, you'll pull across a lot of water with it.  In fact, the stoichiometry on that is two molecules of sodium, one molecule glucose pull across about 210 molecules of water, and that's why oral rehydration solutions have a lot of sodium and just a little bit of sugar.  So it's not just the osmotic pressure, it's also whether or not the molecules in that drink are recognized by the body.  It can be transferred across the gut.

Ben:  Got it, so in terms of the solution, building a better solution, how did you proceed once you realized that this was occurring in the guts of the endurance athletes that you were working with?

Dr. Allen:  Well initially we did what everyone does, I think, naturally, is you delete your sports drink, and that's what we're doing.  We were just using about the concentration that was actually recommended which meant that we were putting our guys at the bottom 3 or 4% sugar concentration.  Unfortunately, the problem with diluting your sports drink is that you also dilute out the sodium in it, and what we were finding is that when we were diluting our sports drink, we were getting signs and symptoms of something called hypernatremia in the athletes I was working with. Essentially, they were losing too much sodium, and over the long haul, it was affecting their performance.  In some cases it was making them sick, and so the evolution was we started like most people do, by diluting up the sports drink, and then we started adding back extra sodium.  And then we started thinking is there an easier way to do it?  Is there a better way to flavor it?  And this whole thing manifested through trial and error.

I was really fortunate to be in the situation where I was working with athletes who were consuming or needing to consume so much of this product, and so the trial and error occurred pretty rapidly and pretty quickly, and what we ultimately realized was that when we used about a 4% sugar concentration, something not so sweet, when we replaced the sodium that they were losing in their sweat or close to it, and when we flavored with really simple ingredients like just freeze dried fruit in the rest of their drink alone, that's when it worked best.  It worked best because everything that we put in their drink was serving some purpose, right?  The fruit was not only a functional food, but it was also a really simple flavoring agent that would wash away very cleanly unlike other flavoring agents, whether they'd be natural or artificial.  You don’t end up having that taste in your mouth all day which can lead to flavor fatigue which can lead to people not wanting to drink their solutions.  We realized that the guys needed more salt, that there was a lot of variability in how much salt people needed, so not only do we add more sodium to their drink, but we also started making savory foods, so that guys can consume salt with their food rather than always relying on really sweet foods when they were training or racing.

Ben:  Now once you're reducing the actual concentration of a sports drink like this, so that the water in the sports drink is able to adequately hydrate the athlete, and so that the electrolytes and the sugars in the sports drinks are able to be utilized.  You've got a very relatively weak solution, right, 4%.  I don't know how many calories does that come out to in say a serving of something like this?

Dr. Allen:  Yeah, that comes out to about 80 calories in half a liter, a hundred and sixty calories in a liter.  That's not an increased amount, that's 40 grams of carbohydrate for every liter that you're consuming.

Ben:  And about how many of those, half a liter, that's 16 ounces, right?  So in most cases I guess, with the athletes I've worked with, they might top of their water intake at maybe twice that, right? Perhaps 32 ounces of water per hour, so if they were using a concentration like this in every drink that they took in, every water bottle that they took in, they might be at a hundred and fifty or perhaps a hundred and eighty calories per hour which is far lower as what you'd see recommended as far as total calorie intake.  So what happens as far as being able to provide enough energy?

Dr. Allen:  It depends on your exercise intensity, right, so if you're getting close to 200 calories in an hour and you're losing about a liter of sweat, the thought is that for a lot of endurance activities, especially if they have a lot of stored glycogen that under four hours, that's probably going to be adequate if you're exercising an intensity that allows you to generate enough heat that you're losing say, a liter to a liter and a half. So here's the question that we started to pose and we started asking ourselves, and I think this is kind of a big misnomer.  The question is are you sweating at a higher rate than you're burning calories, or are you burning calories at a faster rate than you're sweating?  And in the heat, most people are sweating way more than they're burning calories, right?  And you have to be burning 800 calories an hour before you need to consume say 400 calories an hour, right?  So the general rule of thumb is that if you replace about half the calories that you burn per hour, you're probably going to make it, especially in long endurance events because you have plenty of stored fat and plenty of stored carbohydrates you can get us through, so a lot of the carbohydrate that we consume exogenously is there to help maintain our blood glucose and help to supply another source of sugar for packet muscle.

Ben:  Yeah, but something in the tour where you've got athletes going at relatively high intensities for really long periods of time, were they only relying on something like this formulation, this Skratch formulation as their calorie source, or were they doing other things?

Dr. Allen:  It really depends, what we started finding in the Tour de France was that if we look at the total water that somebody was consuming on a day, and what we're trying to do is we're trying to keep them from losing more 5% of their body weight.  So they're still getting dehydrated, they're still not getting enough access to water to be at the same weight before and after the event.  But even after a 5% loss, if you look at all the water they consumed and we look at all the carbohydrate they consumed then we look at how many grams per how many mills, it almost always came out to about 4 or 5% solution, right?  And we're talking about carbohydrate from all sources.  We're talking about carbohydrate from energy bars or from rice cakes or from little sandwiches or whatever they might be eating, and we're looking at water from all sources.  We're looking at water that might craft from the side of the road to drink or even the sports drink we're providing them.

And so what we figured was that a 4% solution because it hydrated very, very well, and it was easily absorbed.  That was the foundation, and if they felt they needed more calories, they could eat their calories, right?  So on average in the tour, our guys are consuming about 80, maybe anywhere from 70 grams of carbohydrate now where to at most a hundred grams of carbohydrate an hour.  A hundred grams of carbohydrate an hour, that's 400 calories, and that's pretty fulfilled.  You almost never have gaze for the average rider at a hundred fifty-four pounds is burning more than 800 calories an hour. So my sense in it was that whole leaked out, if this is what was working at the very, very highest level of sport.  With fittest athletes in the world, this is probably going to work for people who aren't burning as many calories, right?

Ben:  Yeah, so for our listeners if they're doing something like say an Ironman triathlon, they're still going to be getting of the bike, right, and doing a full marathon, and they can't get off the bike with their energy levels necessarily not being topped off even though we'll get into ketosis and fat utilization hopefully here in a little bit.  They're probably going to need to be taking in sources of exogenous calories in addition to what they might be getting from this formula, correct?

Dr. Allen:  It depends on if they drink enough, right?  If they're under-hydrated, then the answer is yes.  But if adequately hydrated, not losing more than 3 to 5% of their body weight, then probably not, but it requires a lot of access and a lot of drink solution to make that happen.  And so I think what happens in many triathlons and a lot of endurance events is not necessarily physiological as much as it is logistical, right?  You just logistically don't have the access to enough fluid.  There seems to be plenty of access to carbohydrate in these events because these people can carry a lot of sugar with them and a lot of food with, but they simply can't carry enough water to meet their sweat rates, and so my general sense of it is that in many of these events, people fall apart not because they get inadequate calories, but they fall apart because they become dehydrated or they become hypernatremic in more rare cases.  So I think one of the best exercises that people can do is to go out there on a hot day, and really try to understand what their sweat rates actually are, and then make a plan.  First and foremost, replace the water they lose, then they can plan to replace the calories that they need.

I think that we for whatever reason, always think about performance and endurance sports about being getting adequate calories.  But the reality is that in the same way that we can survive for weeks without food but only days without water, performance is very much the same.  We fall apart very, very quickly when we don't have enough water.  We fall apart very, very quickly because we get a thermal load, and we overheat.  And so that fluid that we replace is really, really important because I'm maintaining a proper fluid balance.  We can better regulate our core temperature, and ultimately especially for very fit athletes is that regulation of core temperature, that ends up being a big bottle neck.

Ben:  Interesting, so if someone where to go out and perhaps not have access to, for example, the sweat-sodium testing that I'll include more information about at the end of this interview because I did a separate interview with you about the sweat-sodium stuff, but if someone doesn't have access to that, what is the best way for them to determine their sweat rate?

Dr. Allen:  Well for sweat rate, there are two different issues here.  There's your sweat rate, how much total fluid are you losing, and then there's your sodium concentration, how much salt are you losing for that amount of sweat rate or sweat loss.  Sweat loss is really easy to determine by weighing yourself before and after exercise.  So if you lose say two pounds over the course of an hour workout, you know that you've lost approximately 32 ounces of fluid, right?  So weighing yourself before and after exercise is really important.  Now obviously you're burning off some fuel, but the fuel weight is not as significant as the water weight, and so for the most part, you get really close by just measuring a change in total body weight.  Divide that by time, and you get a sweat rate.  So one liter over an hour, that's a liter per hour.  Now the question is what's in that sweat?  How concentrated is that sweat?

Well what's in that sweat?  About 90% of what's in that sweat is simple table salts, sodium chloride.  The rest of it is potassium, magnesium and some calcium.  Essentially what you find in your sweat is what you find in your blood, and what you've primarily found in your blood is mostly sodium, a little bit of potassium, a little bit of calcium, a little bit of magnesium, and so the reality is that you've got to replace that sodium if you want to stay level.  The sodium that we lose in our sweat is highly variable across the population, and so there are tests out there like the one I performed, the time example we can actually measure the concentration of that sodium, and help prescribe what people might need.  But what I've also found is that people listen to themselves, and they listen to their perception of taste for salt, just like you might listen to their thirst.  They can do a pretty good job of replacing what they need, and what you tend to find is that people are all over the place.  Some people like to have salt during exercise, people don't like to have salt during exercise, and before I started doing a lot of these measures, I didn't understand why.

Why was there this individual variability?  As I started doing these tests, I started to realize that people were pretty smarts in terms of listening to their bodies.  And that when they did, they covered their basis.  But when they didn't, they tried to do everything by pure numbers.  They tended to make mistakes and fall apart.

Ben:  So you are a fan of basically drinking to thirst versus drinking ad libido, during something like endurance sports?

Dr. Allen:  I am, but I'm also a fan of an advocate, people becoming educated about how much they lose and knowing where they stand.  If you're drinking to your thirst and you're losing only 3% of your body weight over the course of a five-hour endurance event, then you're doing great, and whatever senses are leading you down that path are fantastic, and if you have no problems with your performance and no signs and symptoms of hypernatremia and your body's all good, then whatever you're doing is fantastic.  I tend to follow the world if it's not broken, don't try to fix it.  But what I tend to find works even better is when people have a good sense of feel are given real feedback and good data, they can slowly hone themselves in.  And ultimately training and racing is a trial and error process when it comes to a single individual.  Obviously I come from a scientific background, so for me understanding lurches is really important. Understanding what happens is really important, but what I've realized about coaching individual athletes is that it's not about N equals a thousand at that point.  It's about N equals them, right?  It becomes about the scientific process, it becomes about learning what works for them.  Because if they're an outlier one way or the other, if that's not addressed then you're not really conscious in science.  You're practicing belief.

Ben:  Right, when it comes from the maximum rate of something like carbohydrate oxidation, most studies show that to top of that whatever 240 to 280 calories-ish per hour, and ultimately when an athlete is let's say burning 800 calories an hour, they're not necessarily going to be able to pull off replacing all the calories that they're burning just because the gut can only take on so many calories per hour.  When it comes to water and electrolytes, is there any type of formula or any type of research out there that shows that an athlete is losing an X amount of water and an X amount of electrolytes per hour, and the maximum amount that they can replenish would be X percentage of that?

Dr. Allen:  Yeah, I think the studies that I've read that have tied to replenish what athletes have lost that they can works, right?  You can absorb that fluid through the gut so long as it's at a low osmotic pressure.  So for example what the Skratch product we said about a hundred and sixty milliosmoles, blood is about 280, so even at where our drink is, there's a lot of room for that water to rapidly absorb then.  And since everything in our drink is transportable and we're using a particular fructose and glucose ratio which enhances that carbohydrate absorption, we can get a lot of water to through athletes.  In fact I think that it's easier physiologically to bring on that water than it is to replace or oxidize that carbohydrate.  So I don’t' think that's the problem, but in reality, it's a massive column because logistically people never have enough access to enough fluid to match their sweat rates.

Ben:  Well, actually in an Ironman or a half Ironman or a triathlon, there's aid station full of water every 10 miles in many cases.

Dr. Allen:  Yeah, and one thing that's interesting to me is that as runners pass through these aid stations, how much are they actually getting in, right?  I think that it is available.  Getting the right concentrations though, getting enough sodium that becomes a funny little lab experiment as you're running down the road.  So one of the complaints I've always heard is that while there are a lot of aid stations, people aren't exactly getting what they need, and it's hard to figure it out when you're on the fly, and so maybe what it is is to try to integrate into practice and say, “okay, if I grab this many bottles or this many Dixie cups, this is what I'm getting from this particular source,” and you can on-load either carbohydrate electrolytes throughout their sources.

Ben:  Right, so what it sounds like to me so far is that for the smart athlete who's actually committed to doing well in the sport and maintaining adequate energy levels, they need to (a) determine their sweat-sodium loss and their fluid loss and try to replace as much of that as possible, experimenting in their training to see what it feels like when they're approaching that and also ensuring that they're not using concentrations of fluids that exceed about that 3 to 4% level.  And then as far as an athlete who finds that even when they're replacing that much that's they're still bonking or still running out of calories.

I want to ask you about the glucose-fructose combination that you're using in this beverage and why you're using that, but before I do, is there a specific type of solid food source that mixes well with this stuff, and this is kind of a leading question 'cause I knew I asked you the same thing at Timex camp, and I believe your response was sushi rice?

Dr. Allen:  Yeah, I like sushi rice.  It's not just because I'm Chinese, but with respect to the summary, I think that, yeah.  All within reason, what I advise is based on my own experience and the experience that I had with athletes, but I think it's really important for people to recognize that they are they're own scientific experiment and that in training, you've got to let this stuff out, and you may find that if you over-drink, your performance goes down and you can over-consume water as much as you can under-consume water.  And you can over-consume sodium and electrolytes as much as you can under-consume sodium and electrolytes.  So there's a Goldilocks and three bears scenario for everybody out there, and that there's plenty of time and training to pay attention with this and work this out and come up with a plan.  Once you have a plan, it all becomes experimentation from that point on with respect to your racing.

Ben:  What is the sugar composition or carbohydrate composition of sushi rice, do you know?

Dr. Allen:  It will all break down primarily into glucose.

Ben:  Okay, so with that you're getting glucose.  But in your beverage Skratch, you've got, basically the ingredient label says cane sugar.  Why did you choose that specific sugar source?

Dr. Allen:  We chose that specific sugar choice for a few reasons.  First and foremost, our goal is to have a particular glucose to fructose ratio.  In the small intestine, you have essentially three carbohydrate transporters.  You have a fructose transporter, you have a glucose transporter and you have a galactose transporter, or milk sugar.  Some people are intolerant of milk sugars.  They don't have a lot of the galactose, so we just ignore that as a potential energy source.  If we can find a sugar ratio or a ratio of glucose that does matches the ratio of glucose-fructose transporters in the small intestine, essentially what we get is we get two lanes of traffic.  We get two lanes that we can send carbohydrate down as opposed to one lane.  Let's say the ratio is 50-50 and we have one glucose lane and one fructose lane, then the correct ratio is exactly 50% glucose, 50% fructose, but I think the nature of it is that there are slightly more glucose transporter than there are fructose transporters, and so we have a ratio of sugars to match that. Cane sugar is very interesting because for one molecule of cane sugar or sucrose, that breaks down into one molecule of glucose and one molecule of fructose, and so we now have a way to have a lot osmotic for of both glucose and fructose.  So we use cane sugar to get a 50-50 match of glucose and fructose, and then we add back a little bit of glucose to increase the ratio, so that we have a little more glucose than fructose.

Ben:  Why wouldn't you choose the fructose maltodextrin blend that a lot of sports nutrition manufacturers use, like these long chains of carbohydrate via the maltodextrin and then the fructose that you're using?  I believe when maltodextrin breaks down, it's still using a glucose transporter, and that's the amount of fructose.  Why wouldn't you use maltodextrin?

Dr. Allen:  That's right, so the question is why we don’t use a long chain malto and fructose 'cause you can certainly do that, and the main reason is that it's taste.  At a 4% solution, you're using malto, a long chain.  When it first touches your mouth, it's not going to taste very sweet.  It's not going to taste very good, and so by using cane sugar, we get the same ratio of glucose and fructose, but we vastly improve the taste of the drink.  For us, it's not just about doing the science and saying what's optimal in terms of hydration, but we're also foodies and connoisseurs of what you're going to want to drink over the long haul, and cane sugar and glucose is far superior in terms of taste than a maltofructose blend in my opinion.

Ben:  Now what about an athlete who would want to use something like this for their daily hydration needs, right?  Like the same way that you'd use something like Nuun or any of these other effervescent electrolyte tablets.  Do you get concerned about dumping cane sugar into their body if they're say sedentary or standing around at their office during the day trying to stay hydrated.

Dr. Allen:  Absolutely.  As a professional e-mailer, I once found myself reaching for the exercise hydration mix that we made to just drink 'cause it tasted good, and it’ll like drinking a soda or something, but it's all about context.  We designed this formula specifically to replace fluid loss and electrolyte loss during exercise.  It's not intended to be used casually, it's not intended to be used when you're just sitting around for regular hydration.  It's for that reason that we actually developed our daily electrolyte mix which is half the sugar, it's a 2% solution.  It's mostly just fruit powder, and it has a very small, not an electrolyte because the water that we lose when we're sitting around has almost not electrolyte loss with it.  And so we design our daily drink to flavor water, so that if you're just sitting around, you have something to drink that is a little more interesting than plain water.

But the fact of the matter is that if you're becoming dehydrated and you're not physically active, if you're becoming dehydrated due to an insensible water loss.  Water being lost through your respiration for example, then drinking plain water is perfectly fine.  So we make a big point to say that this is a sports drink and that there is not necessarily a bad food.  There's just bad behavior.

Ben:  Yeah, now why wouldn't you use something like stevia for example in something like this?  Like the daily instead of a sugar?

Dr. Allen:  Yeah, for me it just fundamentally comes down to the taste.  I' not personally a fan of the way that stevia tastes.  It leaves in my opinion, an after taste, and that after taste drives me insane.  Anytime I drink a product with stevia in it and I taste that drink, five minutes, ten minutes after I've had it, it drives my freaking bonkers.  So for me, it has nothing to do with the plant.  It has everything to do with the mouth feel of that product.

Ben:  Gotcha.  I don't know if you're familiar with this, but there's a couple of research studies out there that look into how genetics play a role in people's taste receptors and how stevia may actually taste bitter to some people and then taste perfectly fine to others.

Dr. Allen:  Yeah, I think that I fall into that category of it tastes bitter, it tastes weird to me and I just want to pee all, and so I guess that's maybe one of the lectures of making your own drink products.

Ben:  Yeah, a little bit of a rabbit hole, I know, but I was just curious about your choice of sugars in the ingredients.  Now this of course leads into what for some people I know is probably the elephant in the room.  That's the fact that we've talked on this show a bit about performing in a low carbohydrate state or training low, and even in some cases for athlete who have trained themselves to train in a low carbohydrate state for the glycogen sparing of the fat oxidizing effect to even use that approach in competition to do something like ketosis and either use MCT oil or coconut oil or even use these newer fancy liquid ketone bodies to actually avoid sugars for the most part during exercise. How familiar are you with Jeff Volek's research on fat utilization during exercise and this apparent need for fewer carbohydrates in athletes who have become fat adapted?

Dr. Allen:  Yeah, I'm somewhat familiar with the work.  Obviously, it's not something that I spend a lot of time thinking about.  I think because the sport of cycling that I come from is very different that a lot of steady state endurance sports like a triathlon where you're exercising at a fixed intensity.  Professional cycling is very different because it's very stochastic in terms of the intensity, meaning that at huge, huge undulations and intensity.  You're going from very low intensity to these very sudden quick accelerations, you're constantly back and forth.  Obviously the higher the exercise intensity, the greater the need for carbohydrate.  At lower exercise intensities, we can use primarily fat as a fuel source.  And so in theory, it make a lot of sense to me.  Fat adapting if you're going to be doing very prolonged, very steady state activity, but it doesn't make sense if you're doing prolonged, very stochastic intensity exercise.  At least that's what I found.

What we did on the pro tour was we worked really hard to adapt our athletes when they were training.  So we would restrict carbohydrate, we would glycogen deplete, feed them higher fat diets, but we found that if we didn't start increasing carbohydrate intake in the week leading up to an event and give them very high carbohydrate diets during racing that they didn't do well.  So I think that our compromise was a combination of the two.  We fat adapted when they were training, but we carbohydrate loaded when they were competing.

Ben:  Now these are athletes participating in multiple staged competitions like day after day.

Dr. Allen:  That's right, day after the exercise, but a very, very unique pattern of exercise intensity.  A road race is very, very not steady.  It's high, high, and low in terms of exercise intensity.  In fact, if a triathlon is mostly, I'd say just below the lactate threshold, what's very interesting about a professional road race is that you're never at lactate threshold.  You're either above it or you're under it.  And so while the average intensity of professional road race might be the same as a triathlon race.

Ben:  Right, you're burning more matches though.  You're entering glycolysis more frequently.  Now what I'm interested doing personally because I know that even if I were to drink enough of this Skratch formula to satisfy my hydration needs that I would probably still need some additional calories, and I just know this because I have experimented quite a bit over the course of eleven different Ironman triathlons and the training that leads up to that.  I generally do well, for example, on the bike at close to 400 calories per hour, and what I'm interested in experimenting with is whether I can use the Skratch formulation to maintain really, really good hydration because of this 4% concentration, but then add something like an oil or a fat, like coconut oil or an MCT oil or something like that to bring in some extra medium-chain triglycerides as my additional calorie sources.  So I'm getting just enough carbohydrates to allow myself to stay hydrated and to drive some of that salt into my system, and then also get the additional benefit of the oils.

Dr. Allen:  Yeah, I think the answer, Ben, is yes you can do that.  I think that where I would be careful is be careful when you think about your gastric emptying rate versus your intestinal absorption rate.  When you think about how the GI tract is working during exercise or when you're eating a meal, digestion begins when we start chewing a food or we swallow something.  That goes down to the stomach, and the stomach is really a big reservoir for food, and it's a mixing chamber where foods get digested.

Ultimately, that stuff is liquefied into a kind, and it moves to the pyloric sphincter at a regulated rate, and hopefully at a rate that matches the ability of the small intestine to then absorb that stuff.  Where people get GI distress is when a lot of their calories ends up being in liquid form whether liquid carbohydrate or even fats.  And what happens is in those situations, you can potentially get, depending on the form of food that you eat, a faster gastric emptying rate.  And while we often think about fast gastric emptying rate as a good thing with exercise performance because it means we're able to speed fuel into our body a little faster.

If all of a sudden the stomach is no longer a bottle neck, well the new bottle neck potentially might be the small intestine.  And so if we empty stuff out of our stomach at a faster rate than our intestines can absorb.  Once that stuff is in the intestine, there's only two places it can go, either into the body or out the butt.  So in my form of thinking, you might need something to bind that fat, whether a little bit of carbohydrate or a little bit of rice or even something solid so that…

Ben:  So you could potentially even use one of your sushi rice cake recipes or something like that and just add some extra coconut oil or something along those lines.  Interesting, and you are spot on by the way.  Do you know there's been research that has shown that MCT containing drinks actually have a faster gastric emptying rate than drinks that contain just carbohydrates?  So I do know that fats do indeed speed up the gastric emptying.

Dr. Allen:  Yeah, and one thing that people don't think about is they don't think about a stomach as a reservoir for food as being an advantage, right?  If you can load up your stomach with some of these extra fats and MCTs and they combine to something that holds them there for a little longer and then the stomach begins to digest it.  Essentially now, you have a glucose fat drip, right?  You have your stomach allowing you, another pocket for food as opposed to trying to hold all that stuff in your back pocket, right?

What winds up happening is that the flow of calories and fluid into your body ends up becoming much more steady, and so think about the water and the food stuffs that you're consuming during exercise is traffic flow, and if you have these big periods where there's a big traffic rush, that's when you potentially have an accident.  That's when you start to slow things down.  You have a little meter which is your stomach allowing foods to enter progressively throughout the whole entire timeframe of your exercise, then traffic ends up being smoother, and I think the risk for GI distress ends up being lower, and what you suggested I think can work really, really well.

Ben:  Now another elephant in the room in addition to the potential for fat utilization and ketosis during exercise is this idea that's been presented my Dr. Tim Noakes.  He has a book called “Water Logged”, and I've interviewed him on the show about his feelings that electrolytes, for example, the need for electrolytes is much lower than what we've been lead to believe, and he cites research for example of people who have been in day long marches in the heat and maintained just as high plasma electrolyte levels as they had when they had begun without actually taking in exogenous sources of electrolytes.  He proposes that perhaps the body has larger stores of electrolytes and sodium than we've been lead to believe, and the need for electrolytes are getting marketing from Gatorade or something like that.  So what are your thoughts on that?

Dr. Allen:  Yeah, I think that obviously the human body is really, really resilient, and that there's so many examples of human survival and extreme environmental stresses, and we're basically designed to survive and we're designed to adapt.  Dr. Noakes makes some really good point about that.  That being said, I think there's a difference between survival and optimizing one's performance.  Just because you didn't die doesn't mean you did your best or that you reached your human potential.  And for me, I come from thinking about how do I get this machine to perform at its highest level for the entirety of this event.  I also come for it from the perspective of not just one day of performance, but 21 days of performance in the Grand Tour, or in the case of the triathlete, all the days of that training leading up to that particular event.  There's some good literature out there that shows that chronic sodium depletion over time can lead to signs of over-reaching and over-training.  There's also as we saw with the group of Timex athletes, a huge variability in sodium loss, in sweat, and so you can certainly find populations of athletes who have self-selected to lose very, very little sodium in their sweat.

Ben:  I actually thought it was very interesting.  You brought that up when you were testing the athletes at Timex camp, how genetics may actually influence the sweat sodium loss.  Can you go into that?

Dr. Allen:  Yeah, you know I think that if you look at the history of salt in society, there's a very, very interesting history, right?  This was one of the most precious minerals in humanity, and there were some regions that had very, very high access to salt, and these areas of the world became very, very prosperous, and there were other areas with very little access to sodium, and getting salt was really, really difficult.  Over thousands of years of evolution, I think what happened was that if you were losing a lot of sodium and you lived in an area where there was very little salt, you just died.  You didn't make it, and you didn't have kids that lost a lot of sodium, right?  On the other hand, if you came from a region potentially where sodium access was very high, it didn't really matter.  You could always get what you needed, and so a lot of what we understand about sodium loss and sweat comes from the field of cystic fibrosis, and there's a genotype that's been identified that actually regulates the re-absorption of sodium in the sweat gland.  And while we used to think that it was a training effect or dietary sodium that were the main determinants of sodium sweat loss we’re starting to find that variability in this gene probably predict more of the difference of people than the training effect or the dietary effects.

Ben:  So what it comes down to is it sounds like some people may actually need to take in electrolytes depending on whether or not they’re genetically lose more sodium or don't have these sodium conversation mechanisms, and in addition to that, people need to take into account chronic sodium depletion, like an athlete who is training heavily each day leading up to an Ironman and losing electrolytes consistently each day leading up to that point maybe different than for example use the case of something that Noakes brings up.  The military personnel who maybe has one march in this single month, but isn't necessarily going out and sweating profusely every single day of an Ironman triathlete.

Dr. Allen:  That's right, exactly.  You know I think that Noakes makes a great point, but his point is moved in the big picture, and it's moved in the big picture because you can also say that people can survive and do pretty well, perform very high with two or three days of sleep deprivation, right?  But that doesn't mean that we don't need sleep.

Ben:  Yeah, it makes sense.  Now one other thing I wanted to ask you about, and this is based off of the audio that I'll play after we finish up here with the sweat sodium analysis is customization of the frequency of water intake versus this Skratch Labs electrolyte intake based on individualized sweat sodium losses.  So let's say that someone finds out, I don't know if you have my data in front of you, but I think I was losing somewhere around it was slightly above a thousand as far as, I believe it was millimolars.  Was it millimolars per liter?

Dr. Allen:  It measures at millimolars, but we can convert that to milligrams, and so converting to milligrams, you were at 1,035 milligrams of sodium loss per liter of sweat.

Ben:  Okay, so based on that, how would you go about creating a customized rehydration scenario based off of something like 1,035 milligrams per liter of sweat?

Dr. Allen:  Yeah, so in your situation, I would say, for example, our exercise hydration makes 720 milligrams of sodium per liter.  At 720 versus a thousand, you're replacing about 30% less.  Now for any given day of exercise performance, you would be just fine using our exercise drink because there's no excess point out.  You have stores of sodium, and so there's an acceptable loss of sodium that you can have during an exercise bout before you have any kind of ill consequences.  You're within that acceptable range.  That being said, I think that if you look at it chronically, you can probably say that you can just drink our drink, and if you need extra carbohydrate, make sure that there's salt in that extra carbohydrate and be at 1,000 milligrams of sodium for every liter of solution that you might drink.

Finally, the third way that you can do it is some ratio of our exercise hydration mix and our hyper hydration mix.  We make a drink mix that is essentially equivalent to the sodium content in a bag of celine.  It's the same sodium concentration as blood.  And what we use with that drink is we use it as a way to titrate in extra sodium so that people can get the right ratio over the course of endurance events.  So for example, at 720 milligrams per liter of our exercise hydration mix and at 3,500 milligrams of sodium loss or sodium for our hyper hydration.  For every six or seven bottles of the exercise hydration mix that you would drink, you would need to have one bottle of our hyper hydration to be just over a thousand.  So this in my mind isn't about customizing a drink mix as it is titrating between two solutions.  So for example if you were lower than 720, there was one person in the camp who for example was at 330 milligrams of sodium loss, they would drink some combination of our exercise hydration mix and titrate that out with water.

Ben:  Yeah, that makes sense.  So if that makes sense, so if I was say drinking 32 ounces of water per hour to satisfy my hydration needs, that's like a liter of water per hour, and if I were adding just one of the exercise hydration mixes to that, that would put me at 700 milligrams when in fact I actually need an additional 350-ish milligrams over and above that, so I would have to figure out how to get that extra 350 milligrams of sodium via salt added to any solid food that I might add, or by adding an extra half packet of this exercise hydration mix or something like that?

Dr. Allen:  Yeah, exactly, so for us, let's say in the case of multiple riders on a team, the solution there is to say we're going to make three bottles.  We're going to make bottles with water, we're going to make bottle with our exercise hydration mix, and we're going to make bottles with our hyper hydration mix.

Ben:  Now, how does that hyper hydration mix not create the same type of osmotic pressure issues that were talking about the beginning of this interview as far as the extreme concentration of something?

Dr. Allen:  Because it has less sugar, it only has three ingredients.  It's just the sodium citrate, it's just the cane sugar and glucose, and then it's just mango powder for flavor. So it's really, really simple where as you're trying to put in some other additional electrolytes in our exercise hydration mix.

Ben:  Okay, so that hyper hydration mix still comes out close to the 4%?

Dr. Allen:  It comes out less.  It comes out at about 3%, and we're only using sodium.

Ben:  Right, so I could, for example, use something like the 700 milligrams, the exercise hydration mix, and if I did that for two hours in a row, I might learn that third bottle or that fourth bottle that I took in needed to be the hyper hydration mix instead of the exercise hydration mix that over the course of say a five-hour cycling event, I would average a thousand milligrams of sodium.

Dr. Allen:  That's right, and in your case, it's every sixth or seventh bottle.

Ben:  Okay, interesting, so every sixth or seventh bottle with the bottle being how many liters in the bottle.  Half liter, we're taking about a sixteen-ounce bottle?

Dr. Allen:  It doesn't end up mattering, it's a ratio.  So if your bottles are tiny, or if your bottles are small.  If you're always using the same sized bottle, and every sixth or seventh bottle, you would drink a bottle of hyper.

Ben:  Yeah, it makes sense.

Dr. Allen:  One issue with hyper is that even though it has a high osmotic pressure since it's basically just sodium and glucose.  It works a lot like an oral rehydration solution where we're able to take advantage of the sodium glucose transport to move water in, and so if we didn't have highly transportable molecules in that solution, it wouldn't work.  So if it was a highly concentrated solution with a lot of food coloring in it, then they'd probably be going out the back end.

Ben:  Yeah, it makes sense, out the butt.  Well this is so interesting, I could talk to you forever.  We didn't even get to this new power meter for running that you're creating, this Stryd meter, so I may need to get you on again just to talk about that alone because that's another fascinating thing that we talked a little bit about at Team Timex camp, but I know we're running short on time.

Dr. Allen:  Well, the Stryd meter is really the genius of Li Shang and his engineering team at the older University of Colorado.  I'm just hanging on for the ride and helping him out while I can, but it's a really neat device that measures the center of mass power that is actually distinct from metabolic power, but I think it can be really useful in terms of coaching runners and giving them feedback about their performance.

Ben:  Yeah, cool.  Well maybe I'll just put a link to that in the show notes, and folks can go explore it on their own until we get a chance to talk about it maybe in a future interview.  If you're interested in a power meter for running, it actually is pretty cool stuff.  So Allen, thanks so much for your time.

Dr. Allen:  Yeah thanks, Ben.  Thanks, it was a lot of fun, and best of luck with all you do.

Ben:  Hey, thanks, man.  Alright folks, well if you want to check this out, just go to bengreenfieldfitness.com/skratch for the show notes.  I'll put a link to Allen's book “Feed Zone Portable” and also “The Feed Zone Cookbook”, the Skratch Lab stuff, the infamous “egg-hydration” video and much more.  And again, that's at bengreenfieldfitness.com/skratch with a K, and until next time.  I'm Ben Greenfield, and he's Allen Lim, signing out from bengreenfieldfitness.com/skratch.  Don't hit stop yet, because you're about to hear a little bonus add on from the sweat sodium analysis that Allen did with me a couple of weeks ago at Team Timex Camp.  Enjoy.

[Interview at the Timex Camp]

Ben:  So I'm sitting here with Allen Lim of Skratch labs at Timex Sports Camp, and he's just placed on me two.  What'd you just put on me, electrodes on my forearm?

Dr. Allen:  I put two electrodes on your forearm connected to a nine-volt battery, and basically we’re going to push a little drug into your skin called policarpine.  Policarpine is a culinargic drug, essentially cytokine, and that's the neurotransmitter when you get hot that is released that causes sweat glands to sweat.  So we're actually inducing sweat in the same way that heat would.

Ben:  You're causing just this tiny little area on my forearm to sweat.

Dr. Allen:  That's right, then what we're going to do is we're going to put a little plastic disk onto that patch which is going to form an airtight seal.  There's a tiny hole in the backside of that disk which leads to a capillary tube, and via capillary action, we're going to absorb your sweat without causing any evaporative loss.

Ben:  So all that sweat that comes off of this place where you're inducing sweat is going to get collected in that tiny tube?

Dr. Allen:  That's right.

Ben:  Okay, and then what happens?

Dr. Allen:  Then we're basically going to take the sample out of that tube, put it into a little sodium analyzer and measure how much sodium you lose per liter of sweat.  So we're going to get a concentration of sodium.  If you know what your body weight loss is during a workout, this will help to inform how much sodium and fluid you need to take in during exercise.

Ben:  Gotcha.  Okay, what's the name of this protocol called?  It's just sweat sodium analysis?

Dr. Allen:  This is sweat sodium analysis developed by a company called WesCor.  They use a system, this particular device is called a Macroduct System.  Macroduct System was actually additionally developed to do sodium sweat test in babies for their diagnosis of cystic fibrosis.  So we're just borrowing technology that is used to diagnose another disease, to measure certain concentration in you.

Ben:  And this is something that varies significantly from person to person?

Dr. Allen:  It's something that varies significantly from person to person.  It can be as low as 300 milligrams in a liter.  It can be as high as 2,000 milligrams in a liter, and in cystic fibrosis, they lose up to all the sodium in their blood which is 3,500 milligrams per liter.

Ben:  Wow, it's amazing.  So if it's not cystic fibrosis, is it usually due to, sorry for the sound in here, genetics, and training status, what you've eaten that day?  What’s the biggest thing that plays a factor here?

Dr. Allen:  I'd say just like a variable VO2 Max, about 80% of it is genetics.  The genotype for that is actually named after cystic fibrosis.  It's called CF1, and CF1 determines the ability of your sweat gland to re-sequester your sodium as plasma most through it.  So if you think about it from an evolutionary standpoint, people who grew up in very high sodium-rich areas could lose a lot of salt with little consequence.

Ben:  They would show an allele of this CF1 gene that would actually indicate them to be not heavy sweaters.

Dr. Allen:  High sodium loss, yeah.  And in other area where sodium wasn't plentiful, if you lost a lot of sodium, you would die.  You would literally not make it to have children, and there's this real evolutionary pressure around this particular genotype, and it has some real performance implications.  What I found is that guys who do really, really well in Grand Tours have naturally self-selected to not lose a lot of sodium.  But now that people are getting more in form or able to get people who would normally wouldn't do well in Grand Tours, who normally do well just at the end of the day and get them through big races.

Now besides genetics, other things can affect it.  If you eat more sodium, you're going to have a higher sodium loss, but not appreciably, but it can affect it.  Your sweat rate will affect it if you're sweating really heavily or you're sweating more.  More fluid is pushing through that sweat gland.  Even if you can re-sequester a lot, you can't keep up with the loss.  Gender, probably not.  Age, probably not.  If anything men tend to have a slightly higher sodium concentration as we've seen.

Ben:  Has anyone gotten their genes tested through 23andMe or DNA Fit or something like that, and actually matched up their specific genetic markers with their sodium loss to see if they do present that gene, if they do in fact?  The reason I ask is I have 23andMe data, I'd be curious to see.

Dr. Allen:  Yeah, I haven't seen that data in athletics, but that data exists in the cystic fibrosis world.

Ben:  Interesting, am I holding up the process here, or you're just simply sitting here waiting for it.

Dr. Allen:  Yeah, we're just injecting the drug right now, take another few minutes, and then once that's done, I'll strap.

Ben:  If someone were to listen to this, and they wanted to have this test on, is this just pretty much totally proprietary.

Dr. Allen:  None.  Not at all, there are plenty of exercise physiology laboratories across the country who have the supplement and use this.

Ben:  What's this called, the WesCor?

Dr. Allen:  Yup, it's the WesCor Macroduct System.  Pediatricians, many of them will be able to do this in terms of specific diagnosis and kind chains.

Ben:  Do you ever have athlete who just approach a local pediatrician and ask for this test?

Dr. Allen:  Yes, I've been told that's happened.

Ben:  Really?  That's good to know.

Dr. Allen:  You can come to Skratch Labs, or schedule an appointment with us if you're in Colorado.

Ben:  You guys are in Boulder?

Dr. Allen:  We're in Boulder.  I know that, for example, Colorado Multi Sport in Boulder, Colorado, as part of their fit service, they have the same system, and they'll do it as well.

Ben:  Okay, so I know I'll get this question, so I'm just going to ask it to you.  How is it not like the fox guarding the hen house for someone who makes electrolyte replacement beverage to be telling people how much sweat they lose?

Dr. Allen:  Because first off, it's not a one-sized pixel sort of thing, so for us we don't solve that problem by trying to make multiple different types of sports drinks.  We solved that problem by essentially making two.  Our sports drink which is right at the medium, 800 milligrams, and that helps inform us what our product needs to be for the middle.  But then we have our hyper hydration which is basically celine level drink, and the feedback that we give the people, say your 1,500 milligrams of sweat loss, we know that for every say three bottles of our Skratch drink, you need to have one bottle of our hyper.  And let's say now you're on the other side.  You're at 400 milligram, well we know that for every three bottles of Skratch you drink, you need to have one bottle of water.  So all it does is it allows us to inform people what ratio.

Ben:  Right, you would have the bottle of water if you were experiencing less sodium loss.

Dr. Allen:  That's right, so we're not using this to necessarily push our own product. We're trying to use this to help other people.  And the fact of the matter is that between two very different concentrations of sport drink, any single individual can then titrate the right ratio to make sure.

Ben:  Do you replace what you lose, or do you replace a percentage of what you use?

Dr. Allen:  We goal to try to replace what you lose, but almost always, it's impossible to do so given race logistics, given training logistics.  So there's always some loss.

Ben:  But it's not like food, calories where if you're burning a thousand calories an hour, you can't obviously eat a thousand calories an hour, sweat and sodium is different?

Dr. Allen:  Yeah, well sweat and sodium is actually similar in the same way that you have a storage of glycogen and a storage of fat that'll keep you going.  You also have a storage of water and a storage of sodium, so this sort of stuff only really becomes important after about two to three hours of exercise and severe heat.

Ben:  Like the person going down doing a sprint triathlon, they don't have to head out there with twelve electrolyte pills.

Dr. Allen:  Probably not, it's not going to hurt them.  It may actually help their performance by having more fluid going on, but they're not going to experience the same catastrophic performance decline at someone in another longer distance.

Ben:  Yeah, about two to three hours is where this stuff starts to get really important. Interesting, that's pretty similar to where glycogen deprivation sits into one and a half minimum, two plus hours.

Dr. Allen:  Once you start to tap out your sodium storage, once you start to tap out your fluid storage, then you get trouble, but you can also pre-load on sodium and fluid before an event as well.  A lot of people don’t like to do it because they feel really heavy coming into an event.  But as you hold on to that glycogen and extra water and if you can put on more fluids just through increases in salt and water intake coming into an event, you're going to be better off than if you didn't.

Ben:  Nice, it'll be interesting to check back in here in a little bit, and see what my personal sodium loses are.  I've actually done a very, very rough version of this test a long time ago.  I should only recall if I was a heavy sweater or light sweater, but I think I was mid-range.  So it'd be interesting to see.

Dr. Allen:  Or at least in this situation, we're not measuring sweat rate, we're measuring concentration.  We can do the sweat rate by looking at your weight change over a workout, and you basically assume that's mostly water.  If you have a caloric estimate, you can also subtract out some of the fuel weight, and then you're good to go.

Ben:  Yeah, cool.  Alright, we'll check back in.

Dr. Allen:  Alright, this'll take maybe about two more minutes.

Ben:  Okay, so he just took my band off, and Allen what are you doing with this now?

Dr. Allen:  So I just sucked the capillary tube on to the sensor, and I'm going to flow your sweat onto the analyzer.  The analyzer is basically a really precise volt meter, so we're going to measure the conductance.  Conductance is going to be proportional to your concentration of sodium.  We're going to get that in millimoles.

Ben:  So you're just going to inject my sweat straight into that tube, and it's going into this conductivity analyzer, and that's made by this WesCor.

Dr. Allen:  That's made by WesCor.

Ben:  Just going to give me my sodium millimolars per liter.  This looks pretty precise process to be able to fit the head in the tube over to the syringe.

Dr. Allen:  Yeah, but it fits pretty well.  It’s a little needle thread, and you can see you're at 49 millimoles per liter.

Ben:  49 millimoles per liter, okay.  So what's that coming out to?  Oh, I'm the second highest that you've tested.

Dr. Allen:  Yeah, you say 1,014.  Actually you've come up a little bit, put you at 50.

Ben:  Oh 50, so that means I lose a decent amount of salt.

Dr. Allen: Yeah, a thousand and thirty-five.

Ben: That's awesome 'cause I love salt.

Dr. Allen:  Okay, put this on, too.  I've got some questions for you.  One is that on a scale of one to ten, one being low sweat rate versus ten being another sweat rate. Relative to your peers, are you the type of person who sweats a lot or a little compared to your peer group?

Ben:  I'm about a seven probably.

Dr. Allen:  Okay, next question is at the end of a very long workout, say a six-hour workout, are you the type of person who has no evidence of salt on your jerseys?  One or ten, a ton of salt on your jerseys?

Ben:  Oh, it's almost nothing.  It's really weird.

Dr. Allen:  You don't see a lot?

Ben:  Yeah, I don't see much like the white crossed, all that stuff.  I don't get any of that.  Yeah, I'm going to say a one or a two maximum.

Dr. Allen:  Okay, say 1.5.  How well do you in the heat compared to your peer groups, ten being awesome, one being you suck at heat?

Ben:  How well do I do in the heat?  I would say probably about a five.

Dr. Allen:  Nice, last question.  How do you feel about salt compared to your peer group?  Are you neutral about salt?

Ben:  I freaking love salt.  I have big bags of salt in my counter, and I put it on everything.

Dr. Allen:  So you're like a ten?

Ben:  Yeah.

Dr. Allen:  Alright, so what we're going to do is we're going to take these questions, and we're going to see 'cause I'm just interested if there's any kind of correlation between the answers to these questions and the range of sodium sweat.

Ben:  It's going to be very interesting.

Dr. Allen:  And we'll discuss that tomorrow.  Do a little presentation about that.

Ben:  Cool, awesome.  Thanks, Allen.



In my article The Real Truth About What To Eat Before, During And After Your Workouts & Races, I mentioned a guy named Dr. Allen Lim, and I specifically gave a shout-out to the recipes he invented when Lim was director of sport science for Garmin and RadioShack cycling teams. 

In that article, I talked about recipes like Chocolate & Sea Salt Sticky Bites, Blueberry & Chocolate Coconut Rice Cakes and Crispy Rice Omelets. You can't argue that those don't sound tasty (and yes, when you eat them with coconut oil you can still be in ketosis, you high-fat zealot, you).

Anyways, the photo above was taken a few weeks ago at my Team Timex triathlon camp, during which Lim conducted a cutting-edge sweat sodium analysis on me (which we discuss along with many other nerdy nutrition topics in this podcast episode).

Lim is a sports physiologist, cycling coach, and a founder of Skratch Labs, a manufacturer of performance hydration mixes and the world’s first active nourishment company. Beginning his coaching career with Jonathan Vaughters’ TIAA-CREF cycling development team, Lim developed a method of testing for biological markers of performance enhancing drugs that ultimately led to cycling’s Biological Passport.

Lim was director of sport science for Garmin and RadioShack cycling teams and is the only American scientist to have worked and cooked for teams at the Tour de France. He has not only worked with dozens of top American cyclists to improve their performance and nutrition, but has also worked with guys like Lance Armstrong and George Bush .

Along with Chef Biju Thomas, Lim is also the author of The Feed Zone Cookbook and Feed Zone Portables.

In this episode, you'll discover:

-Why popular sports drinks are mixed in the wrong concentrations, and how this leads to something called “gut rot”…

-Why you may need to add sushi rice to your race day or long workout protocol…

-The physiological reason why “cane sugar” is absorbed so well during exercise…

-Why Allen isn't a fan of stevia…

-How MCT oil and coconut oil could actually speed up gastric emptying (and why that may not be good!)…

-Allen's thoughts on Jeff Volek’s research on fat utilization during exercise and the apparent need for fewer carbs in fat-adapted athletes…

-Allen's thoughts on Tim Noakes’ idea that based on our electrolyte stores and the fact that sodium loss drives sodium extortion that electrolyte intake is useless during exercise…

-How to create a customized sodium and hydration replacement scenario based on your unique sweat sodium loss…

Resources we discuss in this episode:

The infamous “egg-hydration” video

The Feed Zone Cookbook

Feed Zone Portables

Skratch Labs

Stryd power meter for running








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One thought on “[Transcript] – Performance Nutrition, Sweat Sodium And The Secret Hydration Formula Of The World’s Top Endurance Athletes.

  1. Susan a Guardinier says:

    Yeah so everything depends……. Great——while we all wear Depends. Skratch Labs no better. Too much $$$ for what it is.

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