Science in Sport GO Isotonic Energy Gels are 60 ml carbohydrate gels for runners, cyclists, triathletes and team sport players fuelling long or hard sessions. Each gel gives 22 g of carbohydrate from maltodextrin, 368 kJ (87 kcal) and 0.6 g of sugars. Because the gel is isotonic, SiS designed it to be taken without water.
At a glance
| Detail | SiS GO Isotonic Energy Gel |
|---|---|
| Brand | Science in Sport (SiS) |
| Type | Isotonic carbohydrate energy gel |
| Serve size | 1 gel (60 ml) |
| Carbohydrate per gel | 22 g (36 g per 100 ml), from maltodextrin |
| Energy per gel | 368 kJ (87 kcal) |
| Sugars, fat, protein and salt per gel | 0.6 g sugars, 0 g fat, 0 g protein, 0.01 g salt (Orange) |
| Sizes we list | Single 60 ml gels |
| Flavours we list | Apple, Blackcurrant, Fruit Salad, Lemon & Lime, Orange, Pineapple and Tropical |
| Dietary notes | No caffeine in the ingredient list. Sweetened with acesulfame K. SiS lists GO Isotonic gels in its vegan range on its UK site; check the pack. |
What is in GO Isotonic gels
The Orange gel's ingredients are water, maltodextrin (33%), flavouring, gelling agents (gellan gum, xanthan gum), acidity regulators (citric acid, sodium citrate), preservatives (sodium benzoate, potassium sorbate), sweetener (acesulfame K), sodium chloride and an antioxidant (ascorbic acid). Values vary slightly between flavours.
Why carbohydrate during exercise. The Australian Institute of Sport (AIS) lists sports gels in Group A of its Sports Supplement Framework. Its fact sheet explains that carbohydrate taken during exercise supports performance in two ways: it fuels the muscles, and carbohydrate in the mouth signals the brain, which lowers how hard the effort feels.
What isotonic means here. The AIS says a typical sports gel is very concentrated, at about 65 to 75 g of carbohydrate per 100 ml, and most should be taken with water. A small number of gels labelled isotonic are made to be taken without water. GO Isotonic has 36 g per 100 ml, so it is more dilute. The trade-off is volume: you swallow 60 ml to get 22 g of carbohydrate.
One type of carbohydrate. Maltodextrin is glucose-based. The AIS notes that above about 60 g an hour, glucose-based carbohydrate does not add extra performance benefit and can upset the gut, and that products mixing glucose and fructose work better at higher intakes.
Very little salt. Each gel has just 0.01 g of salt, so it is not an electrolyte product. On hot days and long sessions, plan fluids and electrolytes separately; our hot weather hydration guide explains how.
Who it suits
- Runners, cyclists and triathletes in sessions of about 1 to 2.5 hours, where the AIS suggests 30 to 60 g of carbohydrate an hour.
- Team sport players in long, stop-start matches, which the AIS groups with endurance exercise.
- Anyone who wants to fuel without timing gels around drink stations.
- People who want a gel with no caffeine.
Who should check first
- Short sessions: the AIS says carbohydrate is not needed for exercise under 45 minutes.
- Diabetes or blood glucose concerns: talk to your doctor or dietitian before using carbohydrate gels.
- Sensitive gut: practise in training first. The AIS says gels are well tolerated by most athletes and that gradually training your gut can improve comfort.
- Sweeteners: the gel contains acesulfame K.
- Teeth: the AIS suggests rinsing your mouth with water after gels to limit dental erosion.
- Drug-tested athletes: check Sport Integrity Australia guidance and the certifier databases yourself.
How to use GO Isotonic gels
Tear off the top and squeeze the gel into your mouth; no water is needed. SiS suggests 1 to 3 or more gels an hour, depending on your sport or event, to reach a target of 60 to 90 g of carbohydrate an hour, and notes that cold weather may call for more. Here is how the AIS guidelines line up:
- Under 45 minutes: carbohydrate is not needed.
- 45 to 75 minutes: small amounts, including simply rinsing carbohydrate around your mouth.
- 1 to 2.5 hours: 30 to 60 g an hour. Two gels give 44 g.
- Longer than about 2.5 to 3 hours: up to 90 g an hour, ideally with products that mix glucose and fructose.
The gel does not need water, but you still need to drink for hydration on long or hot sessions. The AIS also recommends practising your fuelling plan in training before race day.
How it compares
- SiS GO Energy + Caffeine Gels: the same 22 g of carbohydrate, plus 75 mg of caffeine in the Berry gel. Count it toward your daily caffeine; see our caffeine guide.
- Cyborg Sport Glycoject HBCD: a carbohydrate powder (highly branched cyclic dextrin) you mix into your bottle, so fuel and fluid go down together.
- Rapid Pure Cream of Rice: a rice-based carbohydrate you prepare as a meal before training, not something to take on the move.
Where to buy SiS GO Isotonic gels in Melbourne and Australia
You can buy SiS GO Isotonic Energy Gels online at Supps247 with Australia-wide delivery (see shipping and returns), or order online and click and collect from one of 11 Supps247 stores that offer online pickup. Supps247 has 18 stores, 17 in Victoria plus Richlands in Queensland, so use the store locator to find your nearest. Staff in store can help you compare labels side by side. You can also use our price match guarantee (conditions apply).
How many gels for a marathon?
It depends on your finish time more than the distance, so work it out per hour. If you expect to finish in under about 2.5 hours, the AIS guide of 30 to 60 g of carbohydrate an hour means one to two GO Isotonic gels an hour, at 22 g each. For a longer marathon the AIS allows up to 90 g an hour, but these gels are glucose-based, and above about 60 g an hour that kind of carbohydrate may not add benefit and can upset the gut, so stay around two to three gels an hour or add a glucose and fructose product. For example, a 4-hour runner taking two gels an hour needs about 8 gels. Rehearse the plan on long training runs and keep drinking for hydration.
FAQs
Do you need water with SiS GO Isotonic gels?
No. The gel is isotonic, so SiS designed it to be taken without water. You still need to drink enough for hydration during long or hot sessions.
How many GO Isotonic gels should I take per hour?
SiS suggests 1 to 3 or more an hour, depending on your event. For sessions of 1 to 2.5 hours, the AIS suggests 30 to 60 g of carbohydrate an hour, and two gels give 44 g. Longer events can go up to 90 g an hour.
How much sugar is in a GO Isotonic gel?
The Orange gel lists 0.6 g of sugars. Its 22 g of carbohydrate comes mainly from maltodextrin, a glucose-based carbohydrate.
Do GO Isotonic gels contain caffeine?
No. There is no caffeine in the ingredient list. If you want caffeine, SiS makes separate GO Energy + Caffeine gels.
Are SiS GO Isotonic gels vegan?
SiS lists GO Isotonic gels in its vegan range on its UK site. Recipes can differ by market, so check the pack you buy.
When should I take my first gel?
SiS says the gel is best taken during intense exercise, and the AIS notes gels can also be used just before exercise. For a long race, practise your timing in training so you know how your gut copes.
Label details checked against the official Science in Sport product pages on 19 October 2026. Formulas can change, so always read the label on the product you buy and follow the directions.
Sources: Science in Sport Australia, GO Plus Isotonic Energy Gel 60ml Orange; Science in Sport, GO Isotonic Energy Gels (nutritional information and ingredients); Science in Sport Australia, GO Plus Caffeine Gel Berry; Australian Institute of Sport, Group A supplements: Sports Gels fact sheet; Sport Integrity Australia, Supplements in sport
