Mix Your Own Sports Drink and Minimize GI Distress

As it turns out, it’s really easy to mix your own sports drink with readily available ingredients.

And by understanding a really simple chemistry principle, you’ll be able to mix your own sports drink and tailor it to your specific nutritional needs while minimizing gut issues during a run (bloating, cramps, diarrhea, etc.).

It also explains why some sports drinks, gels, and even different flavors from the same company lead to GI distress while other brands/flavors don’t.

It’s SOOOO fascinating! ?

Let’s start with the base recipe and build our knowledge and understanding from there.

Start With This Recipe

This recipe closely mirrors the caloric, carb, and sodium content of Tailwind, Skratch Labs, and Gatorade Endurance powders (i.e. most sports drinks).

It’s subtly sweet with some lemony tartness.

RecipeNutrition Facts
12oz water
16g maltodextrin
10g fructose
1.5g sodium citrate
2–3 lemon packets
99 calories
25g carbs
350mg sodium

The links take you to the products I’m using (all available on Amazon). If you need a kitchen scale, here’s the one I have.

Outside the United States? If Amazon in your country doesn’t have the same product, search for equivalents using these terms: maltodextrin powder, fructose powder, sodium citrate, or citric acid.

Ideally, you won’t have any gut issues with the recipe above since it’s relatively conservative. If anything, your stomach might tolerate it better than other sports drinks because it has less junk ingredients (that could lead to GI distress).

Start with this recipe and try it on a run. If it meets your nutritional needs, doesn’t jack with your stomach, and tastes good (enough), then let’s hit the #easy button and call it a day.

Feel free to stop reading now.

However, if you want to adjust the recipe, whether that’s to increase the amount of carbs, sodium, or tweak the sweetness/taste, you definitely want to keep reading.

You can’t just change the carbs, sodium, and flavoring willy nilly.

There’s some science involved with choosing the right ratios for each ingredient to minimize GI distress.

Before You Change the Recipe, Know This

Let’s talk about tonicity.

It’s the key chemistry principle to understand when mixing your own sports drink for running (or other endurance sports).

In a nutshell, a sports drink is either less concentrated (hypotonic), more concentrated (hypertonic), or similar in concentration (isotonic) to the concentration of salt and sugars in blood.

This is determined by comparing a sports drink’s osmolarity to the typical range for blood.

TonicityGood ForConcentrationOsmolarity
HypotonicHydration over nutritionLower than blood< 275
HypertonicNutrition over hydrationHigher than blood> 295
IsotonicHydration and nutritionSimilar to blood275–295

Note: If you go further down this rabbit hole yourself, you might see references to osmolality. While slightly different, osmolarity and osmolality are interchangeable in this context (since the values are within 0.5% of each other).

The tonicity determines what a sports drink is good for.


Hypotonic drinks get absorbed by the body the quickest which is why they’re great for hydration. The downside is they contain less carbs per serving than isotonic or hypertonic drinks, so they’re not going to provide enough energy for longer duration activities.

Mix hypotonic drinks when hydration is the priority over nutrition. For example, light to moderate intensity running under 90 minutes.

Because the drink is less concentrated than blood, water gets pulled from the drink and sent to the bloodstream until the drink’s tonicity balances the blood’s.

This is how a hypotonic drink rehydrates the body so well.


The opposite is true for hypertonic drinks.

They can deliver a lot of carbs and energy at the expense of hydration and slower absorption rates (compared to hypotonic and isotonic sports drinks). Most recovery drinks are hypertonic because they provide a lot of calories, carbs, and/or protein more efficiently than eating solid foods with the same nutritional content.

Mix hypertonic drinks when nutrition is the priority over hydration (and your body isn’t being strained). For example, after a run or to pre-load carbs or sodium the days before a race or long run.

During a run, hypertonic drinks should be avoided at all costs. Unless you’re a fan of GI distress. ?

When a drink is hypertonic, it’s more concentrated than blood. To dilute it so that it matches the tonicity of blood, the body pulls water from the bloodstream.

This is why hypertonic drinks (sodas, alcohol, or fruit juices) never seem to quench thirst because they’re actually dehydrating your body.


When it comes to hydration and nutrition, isotonic drinks hit the sweet spot for runners—providing carbs and hydration in one gulp.

They’re ideal for moderate-to-higher intensity runs over 90 minutes. It’s why most sports drinks are isotonic.

Hopefully you now understand the importance of tonicity (and osmolarity) and why you can’t just throw ingredients together.

You might unintentionally create a hypertonic drink which isn’t suitable during a run.

And this explains why certain flavors within the same brand can cause GI distress but not others. The more ingredients you add to a sports drink (i.e. fancy flavors), the higher the tonicity. Based on studies, some flavors of sports drinks (and I imagine gels, too) are actually hypertonic which would explain why certain flavors don’t sit well with the stomach! ?

It’s also why lemon and citrus flavors are really popular. They’re able to add flavor with less impact on tonicity compared to more complex flavors.

Now, back to the original reason you’re reading this section: you want to tweak the recipe.

But how do you change the recipe and ensure the drink is hypotonic or isotonic?

You use a fan dangled calculator I created.

Big thanks to my brother-in-law for helping me dial in the calculations. (His PhD in soil science was worth it just for this!)

Calculating Tonicity

It’s so fancy it gets its own page. ?

Why These Ingredients

When you look at the research and boil it down, a sports drink really only needs three ingredients:

  1. Maltodextrin (a source of carbs)
  2. Fructose (a strategic second source of carbs)
  3. Sodium (the only electrolyte that needs replenishing)

The carbs are for energy and the sodium to keep your muscles firing.

Flavoring, vitamins, or other electrolytes aren’t necessary and actually reduce the effectiveness of the drink (i.e. delivering the most carbs and sodium as efficiently as possible).

Let’s take a look at each ingredient and why it matters.


While you may not be familiar with maltodextrin, you’ve definitely eaten some. It’s used in a variety of foods like soda, beer, dietary supplements, candy, and most sports drinks/gels.

Maltodextrin is easily the star ingredient and rightfully so because:

  • It’s efficient at delivering a high number of calories and carbs per gram.
  • Is easily digestible (reduces GI distress).
  • Is relatively tasteless. At least the type we’ll use.
  • Has a minimal impact on tonicity (compared to fructose).

While it’s considered a complex carbohydrate, it actually functions like a simple carbohydrate because it breaks down into glucose—a simple sugar easily processed by the body.

And a critical source of energy.

In energy metabolism, glucose is the most important source of energy in all organisms.


As a runner, this should be your new favorite ingredient. It deserves to be in the G.O.A.T. conversation.

One thing to note about maltodextrin is that it’s classified by its dextrose equivalent (DE)—ranging from 3 to 20. Maltodextrin is made up of varying length glucose chains. The shorter the glucose chain, the higher the DE, the higher the sweetness, and the easier it mixes in water.

For sports drinks, it seems maltodextrin with a DE of 10 is the most common. Probably because it does a good job balancing sweetness/taste (minimal) with solubility (dissolving easily in water).


If maltodextrin is the star of the show, fructose wins for best supporting actor. There’s a few main reasons for adding fructose to a sports drink:

  • You need more than 60g of carbs per hour.
  • Helps reduce GI distress (in combination with glucose).
  • Sweetens the drink without adding non-essential ingredients.

The first two points being the most important.

The body can only absorb up to 60g of carbs per hour from glucose alone (maltodextrin). But studies show a combination of glucose and fructose not only increases how quickly carbs are absorbed but also the total amount that can be absorbed (up to 90g per hour).

This is because the body absorbs glucose and fructose differently. So while your body is processing glucose it can also process fructose at the same time.

Basically, you have two “energy highways” working side-by-side instead of one.

If you’re running less than two hours, you probably don’t need more than 60g of carbs per hour. However, you will once you start running longer than that.

Now, as much as fructose deserves a best supporting actor nod, there is one big downside: it has a much higher impact on tonicity than glucose.That means you’re not able to cram as many carbs from fructose into a sports drink as you would from maltodextrin.

Sodium Citrate

While you could easily use regular table salt, there are a couple benefits to using sodium citrate instead:

  1. In combination with glucose, it increases sodium absorption better than sodium chloride (table salt).
  2. Has a 30% lower impact on tonicity.

You’ll also notice sodium is the only electrolyte I’m replacing in my sports drink mix. Studies show sodium is the only electrolyte that needs to be supplemented when running.

All the other electrolytes are lost in such small quantities that it doesn’t matter.


Realistically, flavoring is optional. Because fructose is naturally sweet, any drink including it will have a mild sweetness to it.

The sweetness from fructose and neutral taste of maltodextrin make the drink surprisingly palatable on its own (think watered down sugar water). If I really wanted to, I could train my taste buds to drink it as-is. However, the better tasting you can make a sports drink, the more likely you are to drink it during a run (and get the necessary hydration and nutrition).

So wanted to see if I could improve the taste a bit.

Flavoring can come from a lot of different things: Crystal Light, Kool-Aid, fruit juice, flavored syrups, etc.

However, doing so makes calculating tonicity much harder (because of ingredients in unknown quantities). That’s why I wanted flavoring using the simplest ingredients possible.

That’s how I landed on lemon crystals (essentially just citric acid).

It adds some tartness which makes the drink actually taste more like a sports drink than sugar water.

Things to Improve

I feel what I’ve got here is a solid starting point. However, there are some things I’d still like to do.

  • Add scientific references. I read a bunch of research but want to only include the ones that have been highly vetted.
  • Look for other sources of fructose that could improve the fructose to glucose ratio with minimal impact on tonicity.
  • Find other ingredients for flavoring that still make it easy to estimate tonicity.
  • Nail down two recipes. One with less than 60g of carbs per hour and another with more carbs for longer duration runs.
  • Within reason, confirm the accuracy of the osmolarity calculations. My brother-in-law has a plan to do just that!

If you have questions, let me know in the comments. Especially if you try or tweak the recipe. I’d love to hear the recipe you end up using.

41 replies on “Mix Your Own Sports Drink and Minimize GI Distress”

Hello! Thanks for this article!

I’m planning on running a half marathon this fall and have been told that it is a good idea to plan for hydration and nutrition during the race. I started looking into gels and sports drinks. The only trouble is that I have fructose malabsorption, so I can’t use any of it. After researching different sports drink brands, I have realized that everyone puts fructose in their drinks and gels. A half marathon isn’t that long, so I think hydration is more important than nutrition. Maybe I could get away with making my own drink and use that. That’s how I found your article! I was wondering whether you or anyone have any tips or things I should think about when making a fructose-free, glucose-only, sports drink? I understand that I can only absorb 60g of glucose in an hour, so I am limited there, but for a half marathon, I think that will be enough.
Also, one final thing; I live in Norway, so I have no idea what these lemon packs are. Can I substitute it with citric acid?

Thank you for this article. It got me into the rabbit hole of reading about sports drinks & osmolality, and their effets on long distance triathlons (Ironman). I liked the idea of keeping it simple with three ingredients. I created my own calculator for tonicity and I am now slowly cranking up the carbs from 60g to 105g per hour. Thanks again.

P.S. This article provides a good summary on carbs needed vs effort/intensity.

I have been using Malto Fructose mix 80/40g in a 1ltr bottle. It is becoming increasing more difficult to buy Fructose due to health issues. Is the amount of fructose consumed in an energy drink harmful and if so, is there any alternatives.

why it should be harmful?

it is (fast acting simple) carbohydrate

carbohydrates are not bad for your body if you consume just enough to cover energy expenditure (and you don’t have metabolic issues – pre-diabetes, diabetes, etc)

assuming you will be using sport drink to fuel physically activity, it is nothing but beneficial to your body .. fructose in this case is extra beneficial since it allows for adequate fueling (under oncoming energy would be harmful since it adds insult to your body)

jfc you can’t read/listen to advice about nutrition or anything in some context (for genpop which is having fraction of minimal need for movement and is eating in surpluss their whole life .. fast carbs are bad) and then use it as dogma in another ..

You are absolutely wrong. Same studies that were studying glucose and fructose uptakes also state that fructose is dangerous to the health and should be avoided. The studies were only made to proof that mixing glucose and fructose can increase the oxidation rate. It was not conducted with health in mind. Fructose is metabolized by the liver. The liver will store excess of fructose as fat in the l iver leading to a fatty liver which is well known to cause diabetes and cancer and other cardio vascular deseases. at least 1/3 of the world population doesn’t even metabolize fructose properly or at all (fructose malabsorption). the daily total update of fructose (if you don’t suffer from malabsorption) is about 25g. This means that ingesting all the fructose in the usual hourly ratios of 2:1, 1:1 or 1:0.8 leads to overcharging the liver (not mentioning the fructose you ingested before with your meals). You will very likely suffer from metabolic disease if you do this long term. It would be generally a good idea to research a topic properly before posting any recommendation or acting like you know anything about the matter. If somebody ask you about safety of consuming fructose a wise answer would be “I don’t know” – because you obviously don’t know. Be more responsible.

There is a general consense that fructose has negative effects on health. The same studies that show the mix of glucose with fructose increases the potential carbohydrate uptake (due to fructose uses different glucose transporters) mark that the concerncs in regards of health should not be disregarded and require more studies. Fructose i s a very slow carbohydrate that is oxidized by the liver before it can enter the blood stream as glucose and lactate. The body can usually metabolize 25g per day. About 1/3 of the human population suffer from fructose malabsorption and can’t metabolize any or less than 25g of fructose. Overcharging the liver with fructose will lead to a fatty liver (because the fructose is stored as fat in the liver). This is why non-obese people have fatty livers and suffer from related metabolic deseases like high blood pressure, diabetes, liver cancer and more. Fructose digested from fruits has shown to be less problematic because of the special mixture of fructose with glucose and fibres. The max. fructose uptake is usually reached after a single energy gel (assuming you had no fructose in your diet prior to the ingestion of the enrgy gel/drink and don’t suffer from fructose malabsorption). Most athletes can’t handle this fructose levels. Additionally, the same studies stress that the oxidation intake is just improved when ingested by highly trained athletes (athlete that can sustain a high intensity exercise longer than 2.5 hours) and does not seem to have any impact on oxidation rates on common athletes. The only benefit is that glucose combined with fructose seems to lower gastric distress. But the negative health impact does not proof this fact to be of relevance. The same studies that find certain benefits in a minority of highly trained athletes suggest that fructose should be generally avoided for health reasons. The advertisements and the internet world of copy&paste bloggers don’t mention this part of the studies. While fructose was once viewed as a good alternative to glucose in diets studies have showed the dangers of fructose.

Many thousands of endurance athletes have been using gels, drinks and chews to fuel their exercise for quite some time with 33-44.4% fructose, as those are the commonly available formulations from brands like SIS, Maurten, Flow Formulas, etc. I am not aware of any evidence of increased rates of fatty liver disease in endurance athletes compared to the general population and if what you were saying is true, presumably that would be evident. I think it is understood that the liver is not storing fructose as fat when blood, liver and muscle glycogen stores are depleted rapidly during prolonged endurance exercise – instead fructose is used to restore those depleted glycogen levels. It’s all about conext and this website and this article are geared toward endurance athletes wanting to make their own fuel mix. An endurance athlete who is using more glycogen than they can consume during exercise and who is taking a fuel with fructose included to maximize carbohdrate uptake rate for performance reason does not really need to worry about fatty liver disease. On the otherhand, many in the general population leading sedentary lifestyle should not be taking the same products.

FastTalk has a nice website and podcast where experts talk about nutrition and fueling for endurance athletes and they specifically discuss the safety of high carbohydrate drinks and fructose. Here’s a link to one such episode:

Wow, amazing article. I’m a big fan of maltodextrin. Your article was so informative and taught me much about sports drinks. I have started using UCAN corn starch for all my runs and have had good success. Is it possible for you to look at the tonicity of the unflavored UCAN corn starch?

Hi, is there any reason why 100% Glucose and fructose blend isn’t mentioned? Too sweet perhaps?

you mean just using fructose instead of fructose and maltodextrin? if that’s the question, the main reason is because fructose increases tonicity drastically compared to maltodextrin. so you wouldn’t be able to get enough carbs from just using fructose. and yeah, it might be too sweet or not a very good-tasting type of sweet.

maltodextrin is essentially glucose. if you meant 50:50 fructose to glucose then what i shared above still applies. you don’t get as much carbs for your mixture before it gets hypertonic.

Given that maltodextrin and fructose are both polysaccharides, wouldn’t it better to have a monosaccharide like glucose and combine it with either of the polysaccharides to capitalise on immediate absorption plus the processing of the poly at the same time? I’m just testing that out now. But have no idea on its tonicity profile. Shouldnt it be better that the fructose to maltodextrin blends given the immediate availability of the glucose. 🤔

i believe fructose is a monosaccharide which is why it pairs well with malto to allow for greater absorption.

Fructose is only metabolized by the liver. In order to get the fructose to the liver the intestine has to use the GLUT5 glucose transporters. Those are significantly fewer than the SGLT1 which transport glucose. This means GLUT5 transportation system is saturated much earlier and therefore limiting the fructose oxidation rate. This is why fructose is acting so much slower than glucose. You really spread false information here. It#s nothing wrong in admitting that you lack knowledge. But it is wrong to spread wrong information and to counsel people with wrong information.

Awesome article!
I have a very low osmolality Hypotonic solution which seems to be great for hydration. As per your article, I was wondering if I could use this solution as a base and then add other ingredients for longer distance athletes (cycling 100kms+, running 42kms+, swimming3kms+). My pop thinking i start with hypotonic and albeit making this less so, still provide a hybrid solution for longer distances.

absolutely, you can use this as a base and modify depending on the distance. it’s what i did. for general training runs, stick with the base and then when i got into longer marathon training runs i added more carbs and sodium.

Hey nice content and well presented. I have been doing basically the same ratio brew with 60 Dex : 30 Fruc and TruLemon sachet only difference is Ive been using regular table salt for Na and Salt substitute (has Potassium salts included) to get Na 800 & P 200mg per hour (live in the tropics so sweat like a pig). Will read up on the Sodium Citrate benefits you mentioned as honestly never read about it but will now ;-).
Thanks also the calculator it showed my brew above to be hypotonic at just 262 so Ive tweaked the carbs a bit to still maintain Isotonic at 294 but now total carbs/hr = 104g. I will give it a try and see what my body can tolerate as I understand the fitter/better trained you are the higher the carbs/hr you can process (within reason of course ;-))

nice, glad you liked the post and the calculator helped you dial in your ratios better!

That’s a very wrong assumption. The oxidation rate in human bodies is limited for 1g/min (60g/h). The limit is introduced by the availability of glucose transporter protein in the small intestine. No exercise can increase the amount of available proteins in your intestine. Most athletes don’t reach this oxidation rate. Unless you are a highly trained athlete assume that your oxidation rate is at about 40g/h. What you can improve by exercising regularly is to increase your glycogen stores and the oxidation efficiency. The author of this article has really no clue about what he’s writing. If you have the “wrong” body type or metabolic type you will very likely gain body fat by ingesting that amount of sugar during your exercise. The only way to increase the oxidation rate IN THEORY is to add fructose (or any other carbohydrate that uses a different transporter protein) to your nutrition. the downside is that fructose introduces a severe health risk. In addition human can only metabolize 25g per day. At least 1/3 of the population can’t metabolize any or only a few grams per day (fructose malabsorption). Our body is not designed to handle fructose. The studies that proof an increases oxidation rate also state that the effect is only relevant/observable for highly trained athletes (athletes that can sustain high intensity exercise for at least 2.5 hours) and that fructose is generally a problematic carbohyfrate source because of the health risk and the fact that most people can’t digest it properly.

I have a problem! i live in hungary, and there is no sodium citrate! only natrium clorid (sodium chloride NaCl)
how should i replace? how to use calculator in this case? and how changing the dosing?

Alex, looking to keg this up and use potassium chloride and sodium citrate and skip the maltodextrin for a no carb version, which I assume would be Hypotonic. Can you Email for some suggestions?!

Question on your starting mixture. The sodium citrate is listed as 1.5 grams which yields 350 mg. Is this correct


What will be the cost per serving , if we consider a serving is the amount according to the small table above with 12oz of water ?

i tried to find the spreadsheet i used to calculate cost per serving compared to off-the-shelf sports drink but can’t seem to find it. IIRC, this recipe is definitely cheaper than “fancy” sports drinks from tailwind and other niche sports companies and only slightly cheaper than powdered gatorade endurance (what i was using before i started making me own).

however, those calculations were using a more expensive form of maltodextrin that mixes easier in water (the carbomax one i link to). i like it because it’s the quick dissolving kind (it’s fluffier than the regular kind) and mixes better in water. if you were to buy the normal kind of maltodextrin, you’d cut down costs per serving by a good amount.

I’ve read some information about maltodextrin – fructose ratio and i find,
Change the ratio of maltodextrin:fructose to 5:4(1:0.8) and that’s boosted to 74%…a 20% increase.
So,how can i do this? How can i apply this in?
1000ml water and how much gr. Maltodextrin and how much gr. Fructose is the 1:0.8 ratio?

if you use the calculator, use google to convert 1000 ml to US fluid ounces. and then start playing around with the values for malto and fructose.

if you choose a value of 40 for malto, multiple that by 0.8 to get how much fructose to keep the 5:4 ratio (in this example it would be 32). see if that’s enough carbs and the tonicity you want. if not, change the values until it’s the mix you want.

Hey, great info here. going to have a crack at this rather than shelling out for someone else to do it :D Do you mix as needed (in bottle/bladder) cheers

yeah, i have been mixing as needed. it does get a bit tedious if you need to mix more than a few times a week (which i have been lately in this crazy heat). so i’ve considered buying some smaller containers that can hold multiple servings (and marking each serving) of each ingredient. then i can just pour as much as needed without having to use the scale each time. basically, batch measuring out servings of each ingredient.

Would it be possible to pre mix the powder into a bigger jar then just scoop it out pre mixed, or would that not work?

oops, sorry for the delayed response. from my understanding of the food world, that’s not possible for DIYers. essentially, it’s impossible for us to mix all the ingredients so that they’re evenly distributed throughout the mix (i.e. so that one scoop contains the exact same amount of ingredients). there’s really specialized equipment required to do that.

Great article, just what I was looking for! If you were to mix it up good and proper in a large mixing bowl or with an electric food mixer (say, a 1kg batch or less) would the result be “good enough” of a even mix for us amateurs? Surely it’s got to be close enough.

to be honest, i’m not sure. if you wanted to give a whirl and report back, would love to hear!

the other idea is to bulk mix a concentrated liquid version for storage.

Okay so a long time between reports! I tried mixing everything together in bulk which kind of worked. Probably “good enough” but it was hard to tell, plus a bit messy and time consuming. I decided it wasn’t really worth it. Now I just weigh the powers into each bottle as needed.

Another false information. Mixing a powder will always stay mixed unless the crystals are of significantly different sizes. You can also always shake the powder before using it. There is no difference in “industrial” mixing and “home made” mixing. Mixing two or powders will always yield the same result: a mixture of two or more powders. A mixture never guarantees an even distribution of particles. But in the larger scale you don’t experience any difference if there are 2 molecules less glucose than expected. Also, there does not exist any specialized equipment that can control how many parts of a material are included in a scoop. That’s ridiculous, sorry. I’m really angry by the huge amount of false information you can spread. This site should be taken down.

archie, since homogenous powder mixing is functionally impossible at home, one idea is to make a sort of concentrate that you could take in a smaller bottle. so, determine your desired ratio of ingredients dissolve that in a small amount of water, say 50ml, then use that to mix your drink.

i’m not sure how well these ingredients dissolve, so i’m not sure if you could mix it in a small enough amount of water for it to matter, that would be the biggest obstacle.

like if you wanted to dissolve enough of the powders for, say, a 750ml bottle, would 50ml of water be enough? then you could take a little 150ml bottle, mix a third of it with 700ml of water in the bottle and be on your way.

wouldn’t cause ratio issues as long as the powders were all fully dissolved!

oooh, that’s a good idea trying to mix a concentrated version in bulk. i’m going to try that and report back (hopefully after this weekend).

unfortunately not. with the weather getting colder (and me running less recently), i haven’t needed to use this drink mix in awhile.