SiS energy gel review summary: Beta Fuel Gel is a 60 ml energy gel that packs 40 g of carbohydrates and little else. It comes in two flavors – Orange and Strawberry & Lime. The secret sauce of the gel lies in tweaking the maltodextrin-to-fructose ratio from 2:1 to 1:0.8, which the company claims can improve the body’s ability to process ingested carbohydrates without putting additional stress on the digestive system.
Just a few years ago, 20-25 g was considered the optimal amount of carbohydrates in an energy gel. The rule of thumb is to consume 1 g of carbohydrates per kg of body weight per hour. For example, a 60-kg athlete should eat 60g of carbohydrates an hour, about 2-3 energy gels.
With several popular brands and new studies now suggesting that the human body can absorb up to 90-120 g of carbohydrates per hour for maximum athletic performance, it seems like sports nutrition makers are in an arms race to help you pack in as much fuel as possible.
For example, Maurten Sports Fuel encapsulates carbohydrates in a hydrogel, which allows the fuel to bypass the stomach and directly into the intestine for quicker absorption and less gastrointestinal stress. The brand claims that athletes can take up to 100 g of carbohydrates per hour using its hydrogel. Since each Maurten gel contains 25 g of carbohydrates, it means eating four gels hourly.
Britain-based brand Precision Fuel & Hydration offers a 153 g “Jumbo Gel” that contains 90 g of carbohydrates and recommends athletes consume a pack or more per hour.
Super shoes are already prevalent in today’s running scene; now, we have “super gels” as well.
Science in Sport’s (SiS) Beta Fuel Gel is another such effort. It packs 40 g of carbohydrates per energy gel and is based on a 1:0.8 maltodextrin-to-fructose ratio. That’s a lot of carbohydrates!
The following is a look at the latest fuel supplement from SiS and my experience after a one-hour tempo workout.
Unlike SiS’ GO, the brand’s original energy gel series (we have also reviewed recently), Beta Fuel Gel is not isotonic.
(The first version of Beta Fuel Gel, launched in 2018, was an isotonic energy gel, but the company transitioned to the current rendition in 2021.)
Here are several points underscored on the product page:

I wasn’t joking when I said super gel. At 60 ml, SiS Beta Fuel Gel provides 158 calories and 40 g of carbohydrates, of which 19 g are from sugar. For reference, a GU energy gel is typically around 30 ml and contains 100 calories and 20-25 g of carbohydrates.

Water, maltodextrin from maize, and fructose are the three main ingredients. Certainly, not a natural gel.

I tried both Beta Fuel Gel flavors – Orange and Strawberry & Lime. They taste very similar, but Strawberry & Lime has a mild tartness. The texture is thicker than the GO series but less concentrated than GU.
Overall, the taste is palatable, but it’s a lot of gel to ingest.
Like other SiS energy gel products, the packaging of Beta Fuel Gel is big, which is understandable since it’s 60 ml. The length is 16cm, so be sure it fits your fuel-carrying method.
The package design is stylish and feels premium. However, I believe the material is thicker than that of the GO series, so it takes a little more effort to tear it open. Not a super big deal as long as you are aware of this slight inconvenience ahead of a race.
When your body is pushed to the limits, it’s best to avoid any annoyance, no matter how minor.

I tested SiS Beta Fuel Gel on a 60-minute tempo run (5-10 seconds faster than the goal marathon pace) on an empty stomach and had two gels – one each at the 15- and 40-minute marks.
For an hour workout, I usually don’t need to refuel, but the primary purpose was to see if my stomach could handle two super gels within a one-hour window.
Some takeaways:
SiS Beta Fuel Gel is a 60 ml energy gel that packs 40 g of carbohydrates and little else. It comes in two flavors – Orange and Strawberry & Lime. The secret sauce of the gel lies in tweaking the maltodextrin-to-fructose ratio from 2:1 to 1:0.8, which the company claims can improve the body’s ability to process ingested carbohydrates without putting additional stress on the digestive system.
Pro: A “bigger” energy gel means you can reduce the number of sachets you have to carry on endurance adventures while still packing in sufficient calories and carbohydrates. After all, athletic performance strongly correlates with the amount of carbohydrates you can consume and process.
Con: However, when switching to a new energy gel, especially an option that provides substantially more sugar, you need to allow your body to gradually adapt.
Just because research studies conclude that the human body can process up to 90-120 g of carbohydrates per hour, it doesn’t mean it’s the undisputed truth.
Running faster and longer requires you to train your cardiovascular system and callous your legs. Same with taking more fuel while at your physical and mental limits. Your gastrointestinal system needs training to adapt.
SiS Beta Fuel Gel is a good product, but be sure your stomach is ready for it.