Comparison summary of SiS Go, Maurten Gel 100, and Huma Original: Huma is best suited for athletes who enjoy fruit flavors and prefer natural ingredients. Maurten’s milder sweetness is an ideal option for marathoners who want to stick with a single brand for the entire race but beware of its high price. SiS isotonic energy gels have a pleasant flavor but best suited for training due to its larger sachet.
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Balancing between fueling sufficiently and not overwhelming your digestive system is one of the key factors determining race-day performance.
Not fueling enough could mean smacking head-first against the dreaded “wall.” On the other hand, an over-aggressive fueling plan that stresses your stomach will likely get you a date with the porta-potty mid-run. Either way, you can say buh-bye to a PB. It’s a fine line.

Energy gel makers have explored various product design philosophies to provide the nutrition your body needs, in the proper amount and via the most efficient physiological pathways. Today, let’s look at three energy gels with stomach-friendly reputations – SiS Go Isotonic Energy Gel, Maurten Gel 100, and Huma Original. We have used them extensively over the years and can attest to their performance regarding delivering energy free of stomach stress.
Before beginning the energy gel comparison, we want to briefly explain why stomach issues are common during endurance athletics.
In super-duper layman’s terms, an upset stomach occurs when food or fluids in your digestive system are not processed correctly.
During a race, three integral systems – muscles, digestion, and cooling – constantly fight for your blood. With resources diverted to maintain muscle function and body temperature, your stomach isn’t in an optimum state to begin with. Now, add dose after dose of sugary, syrupy concoction? You do the math.
Does the source of sugars matter? There are two schools of thought:
As the self-proclaimed best-selling, all-natural energy gel, Huma certainly epitomizes the latter. The company calls its products the “stomach-happy gels,” incorporating only natural ingredients, including the popular superfood chia seeds. Its core marketing message? Natural ingredients are the
Here are the ingredient list and nutritional facts of one of its flavors.

The carbohydrate sources are fruit puree (fructose), cane sugar (sucrose), and brown rice syrup (glucose). Ssugar from natural sources as advertised. The energy gel also provides 1-2 g of dietary fiber, which should theoretically slow sugar absorption, help you avoid big blood sugar spikes and crashes, and make it easier on your digestive system.
What are the pros and cons of Huma Orginal energy gel?
Let’s start with the good. Pros:
Cons:
This relatively young brand was founded with the mission of solving gastrointestinal distress. According to Maurten, carbohydrates encapsulated in a hydrogel can bypass the stomach to the intestines, where they can be absorbed faster without causing digestive issues.
The digestive system consists of the gastrointestinal tract (mouth, esophagus, stomach, small intestine, large intestine, and anus), liver, pancreas, and gallbladder. Each organ moves food and fluids along, processes them into absorbable components, or distributes nutrients to various parts of the body.
By skipping the stomach, Maurten simplified the absorption protocol to eliminate some possible complications during digestion. We have tested Maurten Gel 100 extensively in a mountain ultra, marathons, and workouts, as well as the brand’s Drink Mix, if you are interested in learning more.
Here are the ingredients and nutritional facts of Maurten Gel 100.
40 g sachet provides the following:
Many energy gels in the market consist of at least ten to twenty ingredients with added flavoring, preservatives, and other nutrients. Looking at Maurten’s six listed ingredients, it’s pretty much just sugar, salt, and thickeners.
What are the pros and cons of Maurten Gel 100?
Pros:
Cons:

Isotonic solution: A solution with the same salt concentration as cells and blood. It’s used as intravenously infused fluids in medical patients.
UK-based Science in Sport (SiS) developed its isotonic formula in 2002. The technology “allows the gels to empty from the stomach quickly as no fluid needs to be drawn into your stomach to dilute the gel, providing fast energy.“
Conventional energy gels are essentially highly concentrated sugar water, which requires water to break down. If you don’t drink enough fluids, your body needs to draw water from the gastrointestinal tract to assist digestion, compromising the entire system. However, overdrinking can also be problematic because it lowers your body’s electrolyte concentration. With SiS Go’s isotonic formula, you don’t need water to chase down the gels, the company claims.
We tested the energy gel on a mountain road run on a hot summer day. It was effective and fueled the lengthy session with zero stomach issues.
Here are the nutritional facts and ingredients of SiS Go Isotonic Energy Gel.

The majority of the carbohydrates come from maltodextrin. Compared with other sugars, it requires less water to digest. It is an excellent way to get quick calories without dehydrating.
What are the pros and cons of SiS Isotonic Go Energy Gel?
Pros:
Cons:
Above are three pathways to solving gastrointestinal issues connected to endurance sports fueling. We are comfortable recommending them for endurance athletes that have sensitive stomachs. However, their packaging, flavors, and form factors make them suitable for different purposes.
Huma Original
If you enjoy fruit flavors, Huma could be the choice for you. As a reviewer, we can’t say we’ve tried them all, but Huma does a good fruity energy gel.
The big sachet is reasonably flat, so it’s not too bulky to carry. Just make sure it fits in your shorts and vest pockets. For multiple-hour adventures in high temperatures (ultras, for example), Huma is ideal to keep you topped up and ready to grind.
Maurten Gel 100 Hydrogel
If you like to keep things simple and just stick with one energy gel brand for an entire run or race, we recommend Maurten Gel 100. Its mild taste allowed us to eat 6-7 packs for marathons without overwhelming taste fatigue.
It also provides the best bang for the size out of the three options, delivering 25 g of carbohydrates per pack at a relatively small pack. We recommend Maurten as the best energy gel for marathons if price isn’t a factor for you.
SiS Go Isotonic Energy Gels Energy
If you are out for a 1-2-hours and don’t want to carry a water bottle but still want to fuel, SiS isotonic gels are excellent – pleasant taste and easy on your stomach. However, the lower caloric and carbohydrate content for such a huge 60 ml sachet just isn’t the best option for races when you want to feel light and fast.