Running a marathon isn’t just about clocking the distance, it’s about fuelling smart from start to finish. Whether you’re training for your first 42.2km or chasing a personal best, energy management is the key to getting the most out of your body on race day.

That’s where energy gels come in.

What Are Energy Gels?

Energy gels are compact sachets of fast-absorbing carbohydrates designed for endurance athletes. They help replenish your body’s glycogen stores, maintain blood glucose, and delay fatigue — all crucial during long-distance events like marathons.

During prolonged exercise, your body uses glycogen (stored carbs) as its primary energy source. But these stores are limited. Once depleted, you risk hitting "the wall" a dramatic drop in pace, power, and mental clarity.

Why Isotonic Gels Are Best for Runners?

Not all energy gels are created equal. Traditional gels often require water to help digestion. Without enough fluids, they can cause stomach upset or sit heavy.

FUELR Isotonic Gels are designed to solve that. Each sachet delivers 26 grams of fast-absorbing carbs in a water-based formula, so you don’t need to chase it with a drink. That means better absorption, less risk of GI distress, and simpler fuelling on the move.

Compared to thicker, traditional gels, isotonic gels go down easier and are absorbed faster. They’re ideal for marathons, where hydration stations can be spread apart and digestion can become more sensitive over time.

When Should You Take an Energy Gel?

As a rule of thumb:

• Take 1 ISOTONIC gel every 20–30 minutes (that’s around 2–3 gels per hour)

• Or 1 ISOTONIC gel every 6–7km

• Add 1–2 caffeinated gels during the race when you need a mental and physical lift.

• Always trial your fuelling strategy in training, never on race day

Here’s a photo of our FUELR Marathon Gel Guide to help you plan your intake and timing.

At FUELR, our gels are designed specifically with performance in mind no bloating, no crash, no sticky mess.

• FUELR Isotonic Gel: 25g of fast-acting carbs with no need for water

• FUELR Caffeinated Gel: 200mg natural caffeine + performace-dosed beta-alanine and L-Citrulline for a boost when it counts

• Easy-open, no-mess nozzle, clean enough to pop back into your pocket mid-run

• Great-tasting flavours designed to go down easy even late in the race

Whether it’s your first marathon or your tenth, a dialed-in fuelling plan can be the difference between finishing strong and fading early.

Fuel smart. Finish strong. 

Explore our marathon-ready gels → https://fuelr.au/collections/running