GU Energy invented the running gel in 1993. Three decades later, Roctane is still its most refined formula for long, hard efforts: more sodium, caffeine and targeted amino acids to delay muscle fatigue. Here's what this gel is really worth on long trail runs and demanding marathons.
GU Roctane is GU Energy's technical gel: 125 mg of sodium, 35 mg of caffeine and amino acids (OKG, beta-alanine) designed for efforts over 3 hours. Its thick texture calls for water, but the maltodextrin/fructose ratio optimizes absorption and digestibility, even at moderate intensity. At ~€2.80 a packet, it's a premium gel that earns its price over long distances, not in everyday training.
Roctane stands apart from GU's standard gels with three extras: a higher sodium dose (125 mg vs. 55 mg in GU Original), amino acids (OKG, histidine, beta-alanine) and, in the caffeinated flavors, 35 mg of caffeine per packet. All of it fits in a 32 g packet for 100 kcal.
OKG (ornithine alpha-ketoglutarate) is an amino acid that acts as a glutamine precursor and plays a role in recovery and in reducing muscle fatigue during prolonged efforts. Beta-alanine helps buffer lactic acid. The amounts per packet are small, but these additions are what make Roctane a technical gel rather than a classic hydration gel.
Roctane's texture is thick, halfway between a liquid gel and a cream, and slightly denser than hydrogel-style gels like Maurten. It can catch you off guard the first time, especially if you're used to runnier gels. With water (50 to 100 ml recommended per packet), it goes down easily even at a sustained effort.
Trail Mix is the most neutral flavor: notes of hazelnut and vanilla, mildly sweet, with no strong chemical aftertaste. Jet Blackberry has a bolder berry profile, pleasant for the first few packets, but it can get old after 4 to 5 hours of effort. Cold Brew Coffee is the most popular of the caffeinated flavors: the coffee taste does a good job of masking the sweetness. Cherry Lime is tangy and refreshing, especially nice in hot weather.
This is where Roctane shines. Combining maltodextrin and fructose in a 2:1 ratio optimizes absorption by using two different metabolic pathways, so you can absorb more carbs per hour without saturating your gut transporters. In practice, digestibility stays good even at intensities below ventilatory threshold 2, which isn't true of every concentrated gel.
On efforts over 3 hours (trail, ultra, slow marathon), the sodium dose helps with fluid retention and replaces salt losses better than standard gels. That's Roctane's concrete edge over a Naak Ultra Energy or an Overstims Coup de Fouet: the electrolytes are built right into the gel.
| Gel | Format | Carbs | Sodium | Caffeine | Price/unit |
|---|---|---|---|---|---|
| GU Roctane | 32 g | 21 g | 125 mg | 35 mg | ~€2.80 |
| Maurten Gel 100 | 40 g | 25 g | 55 mg | 0 | ~€3.50 |
| Naak Ultra Energy | 45 g | 23 g | 70 mg | 0 | ~€3.20 |
| Overstims Coup de Fouet | 25 g | 26 g | 40 mg | 0 | ~€1.60 |
| Baouw Barre Extra | 50 g | 28 g | Varies | 0 | ~€2.50 |
GU Roctane is a technical gel for runners who want more than just carbs: the high sodium dose, the caffeine option and the targeted amino acids make it a solid choice for demanding marathons and trail runs over 3 hours. It doesn't beat Maurten on pure digestibility or the Overstims Coup de Fouet on value for money, but it fills a distinct niche between the two. You'll find it in our roundup of the best gels of 2026.