One of Gu’s many flavors.
One of Gu’s many flavors. (Tim Tomkinson)


One of Gu’s many viscous flavors.

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A sugary fuel used during races and serious training, typically packed into sealed foil pouches. Endurance athletes must ingest large numbers of calories in the field to avoid bonking, the sudden loss of energy that results from depleting glycogen stores in muscles. Solid food can be difficult to stomach during exertion, and drinking enough calories can lead to bloating and frequent elimination. Gels were developed to occupy the middle ground. Tim Noakes, an exercise scientist and author of 1985’s authoritative Lore of Running, concocted prototypes in the eighties. Gu Energy Labs introduced the original consumer gel in 1993 and became synonymous with the category. Early on, gels went for a straight-from-the-lab mystique; these days the trend is headed in the other direction, with companies like Honey Stinger and UnTapped touting ingredients like honey and maple syrup.

Hunger Games

Gels are just one fuel option. Here’s what 2,000 competitors consumed at the 2014 Ironman World Championship in Kona, Hawaii. 

98,046 bottles of water

10,848 packets of Gu Roctane gel

9,600 Bonk Breaker bars

8,220 packets of Gu Chomps

147 pounds of pretzels 

75 cases of bananas

Too much cattle colostrum (a coveted performance enhancer among tri geeks)

From Outside Magazine, August 2015 Lead Photo: Tim Tomkinson