If you've ever hit the wall mid-run - legs gone heavy, pace collapsing, brain foggy - you already know what happens when your body runs out of fuel. Energy gels exist to stop that from happening. They're the most practical, portable way to keep carbohydrates flowing during a long run or race, and they've become a staple for anyone training beyond 60 minutes.
The problem is that walking into a run shop (or browsing online) and staring at a shelf of 15 different gels is genuinely confusing. Different carb sources, different textures, caffeine or no caffeine, 20g or 40g - it's a lot. This guide cuts through it. We'll explain how gels work, how many you need, what to look for, and which brands are worth your money in South Africa.
What Are Energy Gels?
Energy gels are small, concentrated sachets of carbohydrates designed for consumption during exercise. Most contain between 20–30g of fast-absorbing carbs, along with electrolytes and sometimes caffeine. They're engineered to be digested quickly without sitting heavily in your stomach - which is why they're the go-to fuel for racing rather than, say, a banana or a peanut butter sandwich.
The carbohydrates in gels come in a few different forms: maltodextrin, glucose, and fructose are the most common. Some gels use a single source; others blend two or three. The blending matters, and we'll get to that shortly.
They're not meant to replace a full meal. They're designed to top up your glycogen stores while you're on the move, buying you another 30–45 minutes of quality running before your body starts screaming again.
Why Runners Use Energy Gels
Your body stores carbohydrates as glycogen - in your muscles and liver. That glycogen is your primary fuel source during moderate to high intensity running. The issue is that your body can only hold so much of it. Most trained runners have roughly 90 minutes worth of glycogen available at race pace.
When those stores run out, performance doesn't just dip - it falls off a cliff. Runners call this "hitting the wall" or "bonking." Your pace slows dramatically, your legs feel like concrete, and your brain starts suggesting you walk, sit down, or retire from running entirely.
Gels are the most efficient way to delay and prevent this. By taking in 30-60g of carbohydrates per hour during a long run or race, you keep your blood glucose stable and your muscles fueled without relying entirely on dwindling glycogen stores.
This is why you'll see every serious runner in a half marathon or marathon carrying gels. It's not a preference - it's a physiological necessity.
How Many Energy Gels Do You Need?
The short answer: it depends on how long you're running.
| Duration | Fueling Strategy |
|---|---|
| Under 60 minutes | Usually none needed |
| 60–90 minutes | 1 gel (around 45 minutes in) |
| 90 minutes – 2 hours | 2–3 gels |
| Marathon (3–5+ hours) | 6–8 gels |
The general guideline is 30-60g of carbohydrates per hour of running. Most standard gels contain 20–25g, which means you'll typically be taking one every 30–45 minutes on longer efforts.
It's worth noting that your gut needs training just like your legs do. If you've never practised fueling during training runs, don't debut 7 gels on race day your stomach won't thank you for it.
How to Choose the Best Energy Gel
With dozens of products on the market, here's what actually matters when comparing gels.
Carbohydrate Type
Not all carbohydrates absorb the same way. Your gut has separate transporters for glucose (and maltodextrin, which breaks down into glucose) and fructose. When you only consume glucose-based carbs, those transporters hit a ceiling at around 60g per hour. Once you exceed that, the excess sits in your gut and causes bloating or cramps.
Dual-carb gels - those that combine glucose/maltodextrin with fructose - unlock a second transporter and allow absorption of up to 90g of carbohydrates per hour. For marathon and ultra runners who need higher fuel rates, this makes a real difference. Maurten is the most well-known example of this approach. However, Never Second, is also a great option.
Carbs Per Gel
Standard gels typically contain 20-25g of carbohydrates. Some higher-carb options go up to 40g. This affects how many you need to carry and how frequently you need to take them. For shorter races, standard gels are fine. For a marathon or ultra, a higher-carb gel means fewer sachets to manage.
Caffeine vs Non-Caffeine
Caffeine is a proven performance enhancer. Studies consistently show it reduces perceived effort and can improve endurance performance by 2-4%. Most brands offer caffeinated versions containing 25-50mg per gel.
The practical approach: use non-caffeine gels for most of your run, then switch to caffeinated gels in the second half when you need a mental and physical lift. Don't stack multiple caffeinated gels early - you'll spike and crash, and potentially spend quality race time in a portable toilet.
Electrolytes
Sweat doesn't just cost you water - it costs you sodium, potassium, and magnesium. In a South African summer race, electrolyte loss is significant. Most gels include some sodium, though the amounts vary considerably between brands. If you're racing in heat or sweating heavily, gels with higher electrolyte content (or a separate electrolyte strategy) become more important.
Best Energy Gels Available in South Africa
| Brand | Carbs per gel | Carb source | Caffeine option | Best for | Price range |
|---|---|---|---|---|---|
| GU | 22g | Maltodextrin + fructose | Yes | All-round racing and training | Mid |
| HIGH5 | 23g | Glucose syrup + maltodextrin | Yes | Everyday training, fruit-flavour fans | Budget–mid |
| Never Second C30 | 30g | Dual-carb blend | Yes | Marathon, high-carb fueling | Mid–premium |
| Open Fuel | 40g | Maltodextrin + fructose (1:0.8) | Yes | Long races, ultra distance | Mid–premium |
| USN | 26g | Maltodextrin blend | Yes | Beginners, budget training | Budget |
| 32Gi | 21g | Brown rice syrup | No | Long runs, sensitive stomachs | Mid |
GU Energy Gel
GU has been the benchmark for running gels since the 1990s and remains one of the most trusted names in endurance nutrition worldwide. Each sachet delivers 22g of carbohydrates from a dual-source maltodextrin and fructose blend, along with amino acids and electrolytes. The flavour range is the widest of any brand on the South African market - Salted Caramel, Espresso Love, Chocolate Outrage and many more - and the texture hits the middle ground between thick and runny that most runners prefer. Several flavours come with caffeine, making it easy to build a simple fueling strategy around a single brand.
Best for: All-round racing and training from 10km to marathon.
HIGH5 Energy Gel
HIGH5 is a well-established British brand that's earned a loyal following for one key reason: the gels are made with natural fruit juice, which gives them a noticeably lighter and more refreshing taste than most competitors. Each 40g sachet contains 23g of carbohydrates from glucose syrup and maltodextrin, plus electrolytes and optional caffeine. They're slightly bulkier than some brands, but the clean ingredient list and easy-drinking consistency make them a popular choice for runners who find heavily sweetened gels hard to stomach deep into a long race.
Best for: Everyday training, runners who prefer natural fruit flavour, half marathon to marathon.
Never Second C30 Gel
Never Second has quickly built a serious reputation among elite endurance athletes, and it's one of the strongest alternatives to the hydrogel-style products that dominated the market in recent years. Each C30 sachet contains 30g of carbohydrates from a dual-source blend designed for rapid absorption and minimal GI distress - more carbs per gel than most of the field, which means fewer sachets to carry and fewer interruptions in a race. The brand's athlete roster speaks for itself: ultrarunning legend Jim Walmsley fuels his record-breaking hundred-milers on Never Second, and South African mountain biking star Matt Beers relies on them through some of the most punishing stage races on the calendar. If it's good enough for those two, your marathon is well within its range.
Best for: Marathon, ultra distance, high-carb fueling strategies, runners switching from hydrogel products.
Open Fuel Liquid Gel
Open Fuel is a proudly South African brand built around one idea: high-performance fuel with no gut drama. Their liquid gel stands out from the rest of the field in a few ways. First, the carb content - 40g per serving from a 1:0.8 maltodextrin to fructose ratio, which is on the higher end and designed to maximise absorption without overloading your gut. Second, the format - a screw cap rather than a tear-top, which means no fumbling with packaging mid-race and no litter. Third, the consistency - thinner than most gels, which makes it easy to take without water if needed. It's a thoughtfully designed local product that deserves more attention than it gets, and at a price point that doesn't require an elite athlete's budget.
Best for: Long races, ultra distance, runners who want a high-carb local option with clean ingredients.
USN Energy Gel
USN is one of the most widely available sports nutrition brands in South Africa and their energy gel is a solid, no-frills option for runners who are newer to gel fueling or training on a tighter budget. At 26g of carbohydrates per sachet, the numbers are competitive, and they're easy to find at most run shops, pharmacies and online. They won't win any awards for innovation but they get the job done, and for someone still figuring out what works for their stomach, USN is a practical and affordable place to start.
Best for: Beginners, budget-conscious training, casual racing.
32Gi Energy Gel
32Gi is a South African brand that takes a noticeably different approach to gel formulation. Rather than relying on maltodextrin or glucose syrup, their gels use natural brown rice syrup as the carbohydrate source - 21g per sachet - which provides a smoother, more sustained energy release rather than a sharp spike. The packaging is also unique: credit card-sized and snap-open, which means no torn wrappers and no sticky hands. They're WADA-compliant, free from artificial sweeteners and colours, and particularly kind on the stomach, which makes them a favourite among runners with sensitive guts. There's no caffeine option, so if you want a late-race kick, you'll need to pair them with something else.
Best for: Long runs, trail running, runners with sensitive stomachs, sustained energy over sharp spikes.
Energy Gels vs Energy Bars vs Carb Drinks
Gels aren't the only way to fuel a run. Here's how they stack up against the alternatives.
| Product | Best For |
|---|---|
| Energy gels | Racing, fast efforts, convenience during runs |
| Energy bars | Slower training runs, before exercise, hiking |
| Carb drinks | Long endurance events, simultaneous hydration and fueling |
The short version: gels are the fastest and most portable option during a race. Bars are better suited to lower intensity efforts where you have time to chew and digest. Carb drinks allow you to fuel and hydrate simultaneously, which makes them useful for hot races and ultras but more difficult to carry.
Browse energy bars | Browse carb drinks
Common Energy Gel Mistakes
Even experienced runners get this wrong. Here are the most common fueling errors to avoid.
Taking gels too late. If you wait until you feel tired to take a gel, you've already waited too long. Start fueling early - ideally at 45 minutes - before your glycogen stores are depleted.
Not drinking water with your gel. This is important. Gels are concentrated and need water to dilute them and aid absorption. Taking a gel without water can slow digestion and cause stomach discomfort. Take a gel with a mouthful or two of water, not a sports drink - doubling up on carbohydrate sources at the same time can cause gut issues.
Trying new gels on race day. Test your gels in training. Your gut has preferences and it will tell you about them loudly at the worst possible moment if you experiment on race day.
Stacking caffeine gels. One or two caffeinated gels, timed well, can make a real difference. Four or five will make you anxious, spike your heart rate, and likely wreck your stomach.
Skipping gels in training. Gut tolerance to gels improves with practice. If you only ever fuel in races, you're missing the chance to train your digestive system alongside your legs.
Where to Buy Energy Gels in South Africa
You'll find energy gels at most specialist running and outdoor stores, larger sports chains, and online. The advantage of buying online is access to a wider range of brands and flavours, as well as the ability to stock up before a race without having to hunt across multiple shops.
Macgrif stocks a range of endurance nutrition, including GU, 32Gi, Never Second and more - available online with delivery across South Africa. Whether you're preparing for your first half marathon or stocking up for a 100km trail race, everything you need is in one place.
Shop all energy gels at Macgrif
Find the Right Gel for Your Next Run
The right gel depends on your race distance, your stomach, and your fueling goals. GU is a reliable all-rounder. 32Gi suits longer, steadier efforts. Maurten is worth the premium if gut issues have been a problem. And if you're just starting out, USN gives you a low-cost way to figure out what works for you before committing to a case of something more expensive.
Whatever you choose, start practicing in training - your race day self will be grateful.
This guide was written by the team at Macgrif. We stock endurance nutrition for runners across South Africa.
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