Why Proxima C is the BEST Fuel for Ultra-Runners

Proxima C Endurance Fuel
Proxima Centauri is a red dwarf star and the closest star to our sun.  Of all the types of stars, red dwarfs burn through their fuel supply the slowest.  Red dwarfs, like Proxima Centauri, will likely be the last beams of light in the universe.  When all other stars fade away, red dwarfs, like Proxima C, will remain.

Ultraverse Supplements has released its LONG-awaited endurance fuel – Proxima C Endurance Fuel. Proxima C was formulated explicitly with ultra-runners in mind. Our goal was to leave no stone unturned and create a no-expense-spared ultra-endurance fuel that is simply the best.  

Every ingredient and every quantity of those ingredients was meticulously scrutinized and compared against the latest science as it applies to ultra-endurance performance. No corners were cut with Proxima C, resulting in a fuel that sets a new standard for ultra-runners and other extended-duration endurance athletes.

I know; it’s easy to talk and make big claims. So, what exactly makes Proxima C the best ultra-endurance fuel on the market? 

Let’s find out.  

Proxima C is a multiple transportable carbohydrate solution.

Multiple transportable carbohydrate solutions are solutions that contain more than one type of carbohydrate. It’s no secret that multiple transportable carbohydrate solutions are ideal for endurance fueling compared to single carbohydrate solutions. 

Using a single source of carbs during endurance exercise can cause specific carbohydrate transporters to become saturated. In contrast, multiple sources (working with various transporters) allows for a higher carbohydrate intake without oversaturation.

Ingesting multiple types of carbohydrates can dramatically improve oxidation rates; studies suggest up to 75% (Jeukendrup, 2014). These solutions also lead to less gastrointestinal distress than their single-carb counterparts. That’s 75% more usable energy without causing gastrointestinal issues when done correctly. As a result, studies consistently demonstrate improved endurance performance and reductions in fatigue when using multiple carbohydrate sources compared to single carb solutions.  

During ultramarathons, an ultra-runner should aim to ingest 70-90 grams (240-360 kcal) of carbohydrates/hour, depending on gut tolerance. 

Aiming for that 90 range is recommended, but doing so with single carbohydrate solutions is highly unlikely without causing stomach issues. Proxima C uses four different carbohydrates – all with unique advantages for endurance, and more specifically, ultra-endurance athletes.  

Proxima C’s optimal four carbohydrate blend was formulated for the long haul.

Carbohydrates Used in Proxima C Endurance Fuel

Cyclic DextrinCyclic Dextrin in Proxima C Endurance Fuel

Cyclic Dextrin (aka Cluster Dextrin) is the primary carbohydrate source in Proxima C Endurance Fuel. Cyclic Dextrin is a highly branched form of carbohydrate made from amylopectin. This unique branching is responsible for much of what makes Cyclic Dextrin a tremendous fuel source for long efforts.   

Compared to more traditional carbohydrates such as maltodextrin, glucose, and fructose, Cyclic Dextrin presents many advantages for endurance athletes. Let’s touch on a few of them!

1. Faster Gastric Emptying Time and Reduced Gastrointestinal Distress

Have you ever been in a training session or a race and felt like your carbohydrate drink was just “sitting” in your stomach? Digestion is impaired and slowed during physical activity, and heat exacerbates the issue. Cyclic Dextrin has a significantly faster gastric emptying time than other forms of carbohydrates because of its highly branched structure. Faster gastric emptying time equals less bloating and less gastrointestinal distress. 

This is a pretty big deal considering the most common reasons people give for DNFs during ultramarathons are G.I.-related issues. Additionally, during a 100-mile ultramarathon, most participants admit to having G.I. distress that negatively impacts their performance. 

Cyclic Dextrin causes virtually no gastrointestinal distress, and the frequency thereof is comparable to ingesting water alone. Studies comparing Cyclic Dextrin to traditionally used carbs during endurance exercise show that Cyclic Dextrin drastically decreases G.I. disturbances (Takii et al., 2004).

2. Reduced Perceived Exertion

According to a double-blind study comparing 15g of Cyclic Dextrin vs. 15g of maltodextrin on perceived exertion during endurance activity, perceived exertion was significantly reduced in the Cyclic Dextrin group (Furuyashiki et al., 2014).  So not only does Cyclic Dextrin prevent stomach issues, it makes endurance exercise feel easier. 

3. Increased Time to Exhaustion

A study by Shiraki et al. (2015) on elite swimmers compared the influence of Cluster Dextrin vs. glucose on time to exhaustion during endurance swimming. The study’s results showed a whopping 70% increase in time to exhaustion in the Cluster Dextrin group!  

Summary of Cyclic Dextrin

As you can see, Cluster Dextrin is a fantastic carbohydrate with tremendous benefits for extended duration exercise, which is why it makes up over 60% of our carbohydrate blend. 

It’s so good that we would have no problem concluding that it is the single BEST carbohydrate for endurance athletes, hands down, no contest. If we had to pick JUST ONE carb to use, Cluster Dextrin would be it. 

Luckily, we don’t have to pick one, and as mentioned previously, the best carbohydrate drink will have multiple carbohydrate sources. It’s no wonder that Cyclic Dextrin recently won the distinguished Ringier Technology Innovation Award in 2020 as an innovative ingredient in sports nutrition for its ability to enhance stamina, reduce intestinal discomfort, decrease perceived exertion, and suppress inflammatory stress in athletes. 

So why don’t all endurance fuels use Cluster Dextrin? Simple – COST! Cluster Dextrin is a registered trademarked ingredient that is much more expensive than conventional carbs. Cyclic Dextrin is typically over 5x as expensive as maltodextrin gram for gram (Wilburn et al., 2021). Therefore, the answer must be cost or lack of knowledge; there’s no other good reason NOT to use it. At Ultraverse Supplements, we only make top-shelf, no-expense-spared supplements designed to give you THE BEST… cost be damned. 

Do you want what’s cheap, or do you want what’s best?  

Lastly, when you consider that Cyclic Dextrin is 5x the price of traditional carbohydrate sources, it’s easy to see that Proxima C provides more VALUE than the other fuels on the market. To learn more about Cyclic Dextrin, its benefits, and how it stacks up to other carbohydrates for endurance fueling, check out both of the following blogs;

6 Reasons Why Cyclic Dextrin is the BEST Carbohydrate for Ultra-Runners

Cyclic Dextrin vs. Maltodextrin: Which is Best for Endurance Athletes?

#2. PalatinosePalatinose in Proxima C Endurance Fuel

When used appropriately, Palatinose is a super-fuel for extended duration exercise. Palatinose is basically a chemically altered variety of sucrose, but this alteration makes all the difference. Palatinose has a glycemic index of about 32, while sucrose is over double that at 67. As a result, Palatinose has minimal impact on blood sugar during exercise.  

Because of this, Palatinose offers some benefits that sucrose does not; First, whatever Palatinose an endurance athlete consumes during exercise will not impair fat oxidation. Studies show that fat oxidation rates are dramatically improved when Palatinose is used in place of other carbohydrates during endurance exercise. Second, Palatinose will not cause big energy swings, resulting in energy crashes, which are common when using exclusively high glycemic carbohydrates for endurance fueling.

A study by König et al. (2016) compared various endurance performance outcomes on male cyclists using either 75g of maltodextrin or 75g of Palatinose. The Palatinose group maintained more stable blood sugar and higher fat oxidation rates during cycling, which resulted in improved cycling performance compared to the maltodextrin group.  

Like Cyclic Dextrin, Palatinose is another trademarked ingredient and, therefore, on the pricey side. 

This likely explains why it’s very rarely seen in endurance fuels. The other reason Palatinose is rarely utilized is likely because Palatinose BY FAR stands to benefit endurance exercise that is very long in duration, more so than any other type.

To learn more about Palatinose as it relates to ultra-endurance sports and why it’s a fantastic compliment to the Proxima C four carbohydrate blend, check out Palatinose for Ultra-Running – A Super Fuel for the Long Haul and Three Worthwhile Benefits of Palatinose for Endurance Athletes.

#3 & #4. Fructose and Dextrose

Remember, dextrose is basically glucose – chemically, they’re identical. So, essentially they are the same thing, just sometimes referred to by different names. Additionally, sucrose is glucose and fructose bonded together. So, glucose and fructose can be separate, OR they can come in the form of sucrose which combines them via a glycosidic bond. Sucrose is literally table sugar.  

Fructose and glucose (dextrose) have proven to be an effective combination resulting in high carbohydrate oxidation rates when combined for endurance fueling. MORESO, than sucrose and glucose. I know that’s confusing. But essentially, this means that combining dextrose and fructose is more effective than combining sucrose (bonded glucose and fructose) with more glucose (dextrose). The reason I point that out is that some of the most popular endurance formulas on the market use sucrose and glucose as their primary (or entire) source of carbohydrates (Tailwind, Gatorade).  

Proxima C uses the more scientifically proven combination of fructose and glucose (no sucrose) and two other premium, trademarked carbohydrates (mentioned earlier) that are especially beneficial for ultra-runners. Why do so many use sucrose? Well, it’s SUPER cheap – as I said, it’s simply white table sugar. That’s not to say it’s not effective, but it would never be my choice for a primary fuel, let alone exclusively. There are certainly better options.

Fructose utilizes a unique transporter called the GLUT5 transporter. The sole purpose of the GLUT5 transporter is to metabolize fructose. When an endurance fuel doesn’t incorporate fructose in its formula, it fails to take advantage of an additional carbohydrate transporter and, therefore, an additional energy source. This is the equivalent of having a reserve fuel tank and cutting the line.

Proxima C has the best electrolyte profile on the market.

When formulating Proxima C, the goal wasn’t just to make an endurance fuel that also included electrolytes. 

Lots of companies do that. The goal was to create the best electrolyte profile possible. What makes an excellent electrolyte profile?

  1. Using optimal quantities of each electrolyte
  2. Using optimal ratios of each electrolyte
  3. Using the best version of each electrolyte, taking ultra-endurance performance into consideration

Sounds relatively straightforward, right? It’s not as simple as it may seem. Let’s look at how Proxima C checks each of these three boxes.

First, we had to get the quantities right. By far, the most crucial electrolyte when it comes to endurance performance is sodium, so that’s where we knew we had to start and then build off of that. An ultra-endurance athlete should aim to replace at least 600-800 mg of sodium for every liter of fluid consumed. 

Typically an ultra-runner will drink between 500 ml to 1000 ml of fluid/hour, depending on the temperature and conditions. Hyponatremia is a dangerous condition in which the body becomes depleted of salt. This is usually a result of drinking TOO much without sufficiently replacing sodium.  

Proxima C contains 310 mg of sodium/100 calorie serving. We recommend taking at least two servings of Proxima C per hour to meet your electrolyte needs. Keep in mind that food also contains electrolytes, so if you choose to eat real food during exercise, you will acquire some additional salt (and other electrolytes) from that. Proxima C can be used as the sole fuel source during an ultra; in this case, three servings/hour is recommended.  

Check out our blog on determining your sweat rate for how much YOU should drink during endurance workouts. Remember, the quantities of electrolytes in Proxima C were carefully considered to meet the needs of the average individual. You might need more if you are a heavy sweater or exercise in extreme conditions (heat, altitude). This is why determining your sweat rate is essential.  

Once the sodium is dialed in, it’s time to add the other electrolytes in the ideal ratios. What is the ideal ratio? Well, the goal with electrolyte replenishment is just that – replenishment. You are replacing what is lost. Electrolytes are lost during endurance activity primarily through sweat. Therefore, it makes sense that the best electrolyte ratio reflects the ratio of the electrolytes contained in sweat.  

The average individual sweats out about 3-4x as much sodium as potassium. Additionally, an average individual will sweat out about 3-4x as much potassium as they do calcium and nearly twice as much calcium as they do magnesium. Don’t worry; there’s no reason you should know all of that. 

Just know that the electrolyte ratios in Proxima C Endurance Fuel are spot-on (see for yourself below). Undoubtedly, the most important of those ratios is the sodium: potassium ratio, which should be somewhere between 3:1 to 4:1. Proxima C has a ratio almost right in the middle of that – 3.4:1

Finally, once the optimal quantities and ratios are determined, it’s time to figure out the BEST form of each electrolyte for ultra-runners and other ultra-endurance athletes. There are numerous forms of each electrolyte; this is where many companies “skimp.” Well, I should say it’s one of the places companies skimp.

There are numerous factors to consider when determining the best electrolyte for an endurance athlete. Since Proxima C was formulated for ultra-running and other super-long endurance efforts, we focused on a few main points;

  1. Gastrointestinal impact – You might be surprised to learn that many common forms of electrolytes used in endurance drinks are not the most GI-friendly. Any experienced ultra-runner knows that nausea, bloating, diarrhea, etc., can wreak havoc on performance. Therefore, in our minds, it’s a must to use the most gut-friendly form of each electrolyte.  
  2. Bioavailability – Bioavailability is how well an ingredient is absorbed in the body. If a particular form of electrolyte isn’t bioavailable, you’re essentially paying for something you’ll pee out. You might be surprised that many of the common vitamins and minerals in supplements are not very bioavailable. Why do companies use them if they aren’t bioavailable? Again, the answer is cost.
  3. Performance – If certain electrolytes improve endurance-related performance, then we use those over other forms.

What WASN’T a factor when formulating the electrolyte profile for Proxima C?

COST! That’s right. We didn’t even compare the prices of the other forms. Once we determined what was best, nothing else was taken into consideration. Most companies throw electrolytes into their formula using the cheapest varieties to save a couple of bucks/bottle. We are ultra-runners too. We’d rather KNOW we (and our customers) are taking the best.  

So with ALL that being said, here is the electrolyte profile in Proxima C.

Sodium (as sodium chloride and sodium citrate) – 310 mg

Sodium chloride provides chloride (an essential electrolyte), while sodium citrate provides a highly bioavailable form of sodium that increases fluid and electrolyte absorption. Incorporating sodium citrate is far superior to using sodium chloride alone.

Chloride (as sodium chloride) – 330 mg

Potassium (as potassium phosphate) – 85 mg

In addition to providing potassium, phosphates increase oxygen transport to muscles and neutralize acids, improving endurance and reducing fatigue. Typical formulas use the cheaper forms – potassium citrate or chloride.

Magnesium (as DiMagnesium Malate from Albion®) – 10 mg

Magnesium citrate and oxide are what are commonly used. Both oxide and citrate are super-cheap forms of magnesium (hence the high usage). Magnesium oxide has poor bioavailability. Studies suggest that as little as 4% of oxide is absorbed! If you’re not absorbing it, what good is it doing? On the other hand, magnesium malate (what we use) has excellent bioavailability.  

Citrate has good bioavailability, too; however, citrate can cause a laxative effect.

Magnesium malate is very gentle on the stomach resulting in far fewer GI-related side effects than does citrate.  

Other forms such as phosphate, hydroxide, and carbonate are nearly useless due to their terrible bioavailability, while sulfate often results in diarrhea. Bisglycinate absorbs well and results in few G.I. disturbances. However, due to Bisglycinate’s ability to cause a “calming” effect (often used around bedtime), we opted against it due to the likelihood of sleep deprivation during an ultra.  

After comparing the many different forms of Mg and how they relate to ultra-endurance performance, DiMagnesium Malate stood alone as our winner.

Calcium (as DiCalcium Malate) – 25 mg

Calcium carbonate is by far the most common form used in endurance fuels. Again, it is cheap. While carbonate isn’t a bad choice, DiCalcium Malate has superior absorption compared to carbonate. Additionally, carbonate is recommended to be taken with food to prevent G.I. issues, while DiCalcium Malate can be taken on an empty stomach. Compared to calcium citrate, DiCalcium Malate provides a higher calcium concentration, mg for mg, which means less is required to achieve the same result.

Summing up electrolytes in Proxima C Endurance Fuel

Holy #$*&, who knew electrolytes could be that confusing? I realize now that I probably over-explained that….I apologize. But hopefully, this helps you to realize the perfectionistic approach we have taken on EVERY aspect of formulating this product.  

Proxima C contains just the right amount of ornithine to improve endurance performance.

Ornithine is an amino acid that plays an essential role in the urea cycle. One of the primary functions of the urea cycle is to prevent the accumulation of ammonia in the body. Ammonia is converted to urea and excreted when the urea cycle functions properly. During endurance exercise, ammonia accumulates in the body, increasing fatigue and negatively impacting performance. Ornithine improves energy metabolism during endurance exercise and increases ammonia excretion, which leads to improved endurance performance (Sugino et al., 2008).

As is the case with all Ultraverse Supplements products, we ensure that any ingredients we use have a stellar safety profile and are effectively dosed. Various studies prove ornithine has a superb safety profile. 

While diarrhea can be an issue in doses over 6 grams, you’ll never reach even close to that with Proxima C!

The form of ornithine used in most studies and by far the most proven effective form is ornithine hydrochloride (HCL). Proxima C uses 50 mg of ornithine HCL/serving. What’s an effective dose? 2-6 grams. But remember, we don’t want to venture into the 6-gram neighborhood because the last thing an ultra-runner wants is diarrhea.  

So, if you took Proxima C at a rate of two servings/hour for 24 hours during an ultramarathon, you would end up ingesting 2.4 grams of ornithine HCL throughout that event. Perfect.

If you ventured to the higher side and took three servings (300 kcal) of Proxima C for the same event, you’d take about 3.6 grams of ornithine HCL. Again, PERFECT!

In both cases, you are in the effective dose range without coming even close to the lowest range that has shown to cause G.I. issues. 

Studies show that ornithine isn’t very effective in exercise sessions of less than 45 minutes, so you can see why endurance athletes primarily benefit from ornithine supplementation. Proxima C is an ultra-endurance fuel (in case you didn’t realize that by now).  

Proxima is less likely to cause GI distress than other endurance fuels.

Ultra-runners are particularly susceptible to gastrointestinal issues due to the super-long durations they race and train, the jarring nature of running, and the high caloric demands of the sport. As mentioned previously, G.I. issues are the number one reason for DNFs during ultramarathons.

For these reasons, we knew that Proxima C had to be exceptionally easy on the gut. Cyclic Dextrin passes through the stomach faster than carbohydrates like glucose, sucrose, maltose, and maltodextrin (Wilburn et al., 2021). Cyclic Dextrin leads to fewer instances of G.I. distress when compared to any other form of carbohydrate.  

Glucose (aka dextrose) and maltodextrin have been shown to lead to twice as many G.I. disturbances as Cyclic Dextrin (Takii et al., 2004). Cyclic Dextrin has been shown to cause as few G.I. disturbances as water alone (Takii et al., 2004). As you can see, Cyclic Dextrin is in a league of its own in preventing stomach issues, which is one (of many) reasons it makes up over 60% of Proxima C’s four carbohydrate blend.  

Additionally, the remaining three carbohydrates (fructose, dextrose, and Palatinose) were also selected and dosed with the prevention of stomach issues as a top priority.  Lastly, our electrolytes were carefully selected to prevent stomach issues.

There is less risk of palate fatigue when taking Proxima C.

When you try Proxima C, you will likely notice it is less sweet than most (maybe all) of the endurance fuels you have tried. This was intentional, and it is a very good thing. You may be able to run a marathon or a 50k while sucking down super sweet fuels with no issue. But, chances are, when you venture into 100k or 100+ mile territory, you will experience some severe palate fatigue. Palate fatigue during ultra-endurance events is almost entirely caused by excessive sweetness. Proxima C is naturally less sweet than other fuels because of the carbohydrate profile. 

Cyclic Dextrin and Palatinose are significantly less sweet than their counterparts (and more traditionally used fuels) maltodextrin and sucrose. Additionally, we opted for just enough sweetness in the flavor profile to cover the taste of the electrolytes to prevent palate fatigue further. Again, Proxima C aims to prevent issues and improve performance during ultra-endurance activity better than any other fuel! Palate fatigue can be crippling during such activity.

Proxima C leads to better fat oxidation during endurance exercise.

Because the majority of carbohydrates in Proxima C are complex, fat oxidation will be dramatically improved compared to conventional fuels that use primarily (or exclusively) high glycemic, rapidly oxidized, simple sugars. Additionally, it contains Palatinose, which leads to improved fat oxidation when compared to other carbohydrate sources.

As any astute endurance athlete realizes, the importance of efficient fat burning cannot be understated during long endurance bouts. The more fat you can use as fuel during endurance exercise (while still fueling), the longer you will be able to go without totally depleting glycogen, AKA hitting the wall.  

Proxima C improves the immunoendocrine response following endurance exercise.

Taking in carbohydrates during prolonged endurance exercise leads to improved immunoendocrine response. 

That is, hormones and the immune system are benefited from taking in carbohydrates vs. NOT ingesting carbs. 

Ok, great, but what makes Proxima C so unique? The answer is, again, Cyclic Dextrin.  

Compared to other carbohydrates, Cyclic Dextrin decreases stress hormones and inflammatory markers substantially more following endurance exercise (Suzuki et al., 2014). Keeping stress hormones and inflammation in check are significant contributors to the recovery process, and the importance is hard to exaggerate concerning endurance athletes engaging in heavy training.

As if we haven’t given you enough reasons to love Cyclic Dextrin! Can you see why this is a MUST-have carbohydrate in your endurance arsenal? It’s a must-have carbohydrate that we believe we have utilized perfectly in Proxima C Endurance Fuel.

Proxima C Endurance Fuel is the Best Ultra-Running Fuel on the Planet.

Proxima C is unmatched when it comes to ultra-endurance fueling. It’s a product of science, attention to detail, ultra-endurance focus, and an absolute refusal to compromise on quality. 

Ultra-athletes, if you’re looking for the best endurance fuel, you’ve found it.  Try Proxima C Endurance Fuel now!  See the difference it can make in your endurance performance for yourself.  We GAURANTEE you’ll love it.

Proxima C Endurance Fuel


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Jeukendrup, A. (2014). A Step Towards Personalized Sports Nutrition: Carbohydrate Intake During Exercise. Sports Medicine, 44(1), 25–33. https://doi.org/10.1007/s40279-014-0148-z
Schuchardt, J. P., & Hahn, A. (2017). Intestinal Absorption and Factors Influencing Bioavailability of Magnesium-An Update. Current Nutrition and Food Science, 13(4), 260–278. https://doi.org/10.2174/1573401313666170427162740
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Suzuki, K., Shiraishi, K., Yoshitani, K., Sugama, K., & Kometani, T. (2014). Effect of a sports drink based on highly-branched cyclic dextrin on cytokine responses to exhaustive endurance exercise. The Journal of Sports Medicine and Physical Fitness, 54(5), 622–630.
Takii, H., Kometani, T., Nishimura, T., Kuriki, T., & Fushiki, T. (2004). A Sports Drink Based on Highly Branched Cyclic Dextrin Generates Few Gastrointestinal Disorders in Untrained Men during Bicycle Exercise. Food Science and Technology Research, 10(4), 428–431. https://doi.org/10.3136/fstr.10.428
Wilburn, D., Machek, S., & Ismaeel, A. (2021). Highly Branched Cyclic Dextrin and its Ergogenic Effects in Athletes: A Brief Review. Journal of Exercise and Nutrition, 4. https://doi.org/10.53520/jen2021.103100

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