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Race Fueling

What Makes Up A Gu?

It fuels endurance athletes, packs nicely and comes in a plethora of flavors—but how do the ingredients of the popular energy gel actually work?

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It fuels endurance athletes, packs nicely and comes in a plethora of flavors—but how do the ingredients of the popular energy gel actually work?

With help from energygelcentral.com, we take a closer look:

Maltodextrin and Fructose
Depending on the flavor, a single Gu packet contains 70 to 80 percent maltodextrin and 20 to 30 percent fructose. When maltodextrin is combined with fructose, a main sugar naturally occurring in fruit and vegetables, runners reap the carb-energy more quickly—meaning more energy during a long run with less blood being diverted from muscles to aid digestion. Maltodextrin’s high concentration of carbs, combined with very little sugar, makes this pairing ideal, enhancing the sweet factor without the consequences of a sugar crash.

Amino Acids
Gu comprises four protein-building amino acids that fight muscle fatigue. Histidine works against metabolic acidosis, aka a buildup of too much acid in the body, by producing protein that allows the muscles to endure longer workouts. The Branched Chain Amino Acids (BCAA)—leucine, valine and isoleucine—aid protein synthesis, or the conversion of protein into usable fuel.

Citric Acid
When muscles are fatigued, the citric acid cycle is responsible for breaking down and processing amino acids, glucose and fatty acids into ATP—the energy molecule required to keep the body going. The acid itself leaves a tangy, tart taste.

Antioxidants
Anti-aging vitamins E and C (ascorbic acid) slow the body’s oxidation, or decay, process. In Gu, these antioxidants protect muscle tissue from cell damage caused by an oxygen increase in exercising muscles.

Electrolytes
As in most energy fuel products, electrolytes are key to replenishing the loss of salts in the body from excessive sweating. The potassium citrate, sodium citrate and sea salt found in Gu all work to replace electrolyte concentrations in the blood stream, which is regulated by the kidneys. Sea salt also enhances flavor and satisfies the body’s craving for it.

Gellan Gum
This gelling agent thickens and increases the liquid’s viscosity, producing a clinging sensation in the mouth that allows the flavors to linger longer. Similar to flour or starch, it is a polysaccharide—or a long chain of carbohydrate-based molecules that can withstand higher temperatures. It also contributes to the gel’s opaqueness.

Pectin Powder
Pectin powder enhances the distinct silky sensation of the gel. Pectin is also a soluble dietary fiber—it slows glucose absorption by binding to cholesterol in the gastrointestinal tract and adding bulk to the stool, which may explain any sudden bout of runner trots.

Caffeine
Not all Gu energy gels contain caffeine and most packages stick to a 20-milligram dosage in addition to the green tea leaf extract ingredient. The new seasonal Carmel Macchiato flavor packs 40 milligrams of caffeine for an extra boost of speedy fat-metabolizing stimuli.

Herbs
For recovery, chamomile and ginger extract target the muscles and stomach respectively. Chamomile, a natural anti-inflammatory, helps decrease muscle swelling, while ginger soothes the stomach during the rapid digestion of Gu pre-, mid- or post-run.

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