SiS GO Electrolyte Review: Carb and Electrolyte Fuel for Long Sessions

SiS GO Electrolyte is Science in Sport's carbohydrate-and-electrolyte drink powder, the orange-tub product you see clipped to bike bottles and lined up in marathon kit bags. It is not a hydration tablet and it is not a recovery shake. It is endurance fuel: 36g of carbohydrate plus sodium and a few other minerals in a single 500ml serving, designed to keep you topped up with energy and fluid at the same time during a long session. The headline verdict is that SiS GO Electrolyte does its specific job well, mixing cleanly and sitting easily on the stomach for most people, but it is widely misunderstood as a low-calorie electrolyte drink, which it absolutely is not.

The thinking behind it is sound. During longer exercise your body can only absorb and burn so much ingested carbohydrate per hour, and topping up sodium helps you hold onto the fluid you drink. SiS built GO Electrolyte to deliver both in one bottle at roughly a 6 percent carbohydrate solution, the concentration the research has long pointed to for combining energy and hydration. The catch is in the framing: the "electrolyte" in the name leads plenty of buyers to expect a zero-sugar hydration drink, then they are surprised to find 144 calories and 36g of carbs per serving.

Who it is for

GO Electrolyte makes sense the moment a session runs long enough that you need to eat as well as drink. Think runs and rides past about 60 to 90 minutes, long bricks, sportives, marathons and half-marathons, and hard training blocks where you want a simple way to take on fuel without chewing gels. Endurance research broadly supports taking in around 30 to 60g of carbohydrate per hour for efforts of one to two and a half hours, and a 500ml bottle of this lands neatly inside that window (Jeukendrup, Sports Medicine, 2014).

It is the wrong product if you want hydration without calories. For an easy gym session, a hot day at your desk, or simply replacing salts after sweating, you do not want 36g of carbs going down with it. In that case a zero-calorie tablet or powder is the better call, and our best electrolytes UK guide covers those options in detail.

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Ingredients and specs

The formula is a carbohydrate mix making up the bulk of the powder, mostly maltodextrin from maize with some fructose, then a small electrolyte blend of sodium chloride, sodium citrate, potassium chloride, calcium lactate and magnesium oxide. That maltodextrin-plus-fructose pairing matters more than it looks: combining glucose-based and fructose carbohydrates lets the gut absorb more total carbohydrate per hour than a single source, because they use different intestinal transporters (Jeukendrup, Sports Medicine, 2014). At a single 500ml serving you will not be pushing the upper limits of that, but it is a sensible design choice for anyone stacking bottles across a long day.

It is sweetened with aspartame rather than sugar, which keeps the genuine sugar content low even though the carbohydrate count is high. That is a point worth understanding: high carbohydrate does not mean high sugar here, because maltodextrin is a complex carbohydrate, not table sugar.

Taste, mixing and use

In practice, the thing owners praise most is how cleanly it mixes. Plenty of carbohydrate powders clump or leave a gritty sludge at the bottom of the bottle, and GO Electrolyte mostly avoids that if you shake it properly. The flavours are mild rather than intense, which is deliberate: a strong, sharp drink can become hard to stomach hour after hour on a long ride, so the slightly subtle taste is a feature, not a flaw. Lemon & Lime and Orange are the safe, popular picks; Blackcurrant and Tropical have their fans.

There is a faint sweet, slightly syrupy quality from the maltodextrin that not everyone loves, and a minority find aspartame leaves an aftertaste. The bigger practical niggle is cleanup. Because it is a real carbohydrate drink, any leftover liquid goes sticky and can grow unpleasant if you leave a half-full bottle in a warm car. Rinse promptly and it is a non-issue.

On the stomach, the 6 percent concentration is the key. Stick to the recommended 40g in 500ml and most people tolerate it well across long efforts. Make it too strong, as some do trying to cram in more fuel, and you raise the odds of GI discomfort. Mix to spec and it behaves.

Sodium: enough, or not?

This is where honest framing matters. GO Electrolyte carries a moderate sodium level, around 20 mmol/L, which is fine for the average runner or cyclist in temperate conditions where the main goal is fuel with some salt alongside. It is not a maximum-sodium product, and it is not trying to be.

If you are a heavy or salty sweater, or you train and race in real heat, you can lose a lot of sodium in sweat, and losses climb sharply as intensity rises (Baker et al., European Journal of Applied Physiology, 2018). In those cases GO Electrolyte alone may not keep up, and you might pair it with extra sodium or a dedicated higher-sodium product. Treat it as a fuel that also helps your fluid balance, rather than a full electrolyte-replacement solution for a hot ultra. For hydration-led needs specifically, compare it against the zero-calorie options in our best electrolytes guide.

Value

A 1.6kg tub gives you around 32 to 40 servings depending on flavour and scoop, and on a per-serving basis that undercuts taking the same fuel as gels by a clear margin. If you train often and go long, buying the big tub and decanting into bottles is one of the cheaper ways to fuel properly. The 500g tub is the sensible starter size to test a flavour before committing.

Where the value wobbles is when people buy it for the wrong job. Used as endurance fuel it is good value; bought as an everyday hydration drink it is overpriced and over-fuelled for the task. Match the product to the session and it earns its place. You can browse more fuelling and recovery options in our nutrition section, and if you are also sorting out a recovery protein for after the session, our best protein powder UK guide and the best clear whey protein UK roundup are good companions.

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Recommended reads

• Best electrolytes UK
• Best protein powder UK
• Best clear whey protein UK
• Nutrition guides