BEGINNER'S GUIDE TO ENDURANCE FUELLING

Whether you're training for your first 10k, sportive or triathlon, what you eat and drink during exercise will have a direct impact on how you feel, how you perform and how quickly you recover. This guide covers everything a beginner needs to know about fuelling endurance sport — without the jargon.

Why Fuelling Matters (and Why Most Beginners Get It Wrong)

Most beginners underestimate how much energy endurance exercise burns. Running, cycling and triathlon place sustained demands on your body that everyday eating simply doesn't prepare you for.

The most common mistakes are:

• Starting a session without eating anything beforehand
• Waiting until you feel hungry or tired before taking on fuel
• Relying on water alone without replacing electrolytes
• Using products loaded with excessive sugars that cause stomach issues

The good news is that fuelling well is straightforward once you understand a few basic principles.

The 3 Phases: Before, During and After

Before Exercise

Aim to eat a moderate carbohydrate meal 2–3 hours before training. If you're short on time, a single energy gel 15–20 minutes before you start can help top up available energy without sitting heavily in your stomach.

During Exercise

For sessions lasting longer than 60–75 minutes, you need to replace the calories your body is burning. A general starting point is 100–180 calories per hour, taken in small amounts regularly rather than all at once.

Energy gels are ideal here — compact, easy to carry and fast to consume on the move. Pair them with water and electrolytes to support hydration and prevent cramping.

After Exercise

Recovery nutrition is often overlooked by beginners. Within 30–45 minutes of finishing, aim to consume a combination of carbohydrates and protein to help replenish glycogen stores and support muscle repair.

How Many Calories Do You Actually Need?

A common misconception is that you need to replace every calorie you burn. In practice, most endurance athletes can only absorb and utilise around 100–180 calories per hour during exercise.

Consuming more than this — particularly from simple sugars — often leads to digestive discomfort rather than better performance.

Hammer Nutrition's approach is built around this principle: supply the calories your body can effectively use, not the maximum amount possible. This makes fuelling more comfortable and more sustainable across long efforts.

Carbs vs Sugar — What's the Difference?

Not all carbohydrates are the same. Many mainstream energy products rely heavily on simple sugars such as glucose and fructose, which provide a rapid but short-lived energy spike followed by a crash.

Hammer Gel uses complex carbohydrates, which provide a smoother, more sustained release of energy. This helps maintain consistent performance without the blood sugar rollercoaster that can leave you feeling worse mid-session.

For beginners, this distinction matters because digestive comfort during exercise is critical. Products high in simple sugars are a common cause of stomach issues, particularly during running.

Read more: Hammer Gel Fueling Guide →

Hydration and Electrolytes: The Missing Piece

Water alone is not enough during endurance exercise. As you sweat, you lose electrolytes — primarily sodium, potassium, magnesium and calcium — which are essential for muscle function, nerve signalling and fluid balance.

Replacing electrolytes helps:

• Prevent muscle cramping
• Maintain concentration and coordination
• Support consistent energy levels
• Reduce the risk of hyponatraemia (low blood sodium from drinking too much plain water)

For most training sessions, electrolyte capsules or tablets taken alongside water are the simplest solution. In hotter conditions or longer events, you may need to increase your electrolyte intake significantly.

Explore Endurolytes →
Explore Endurolytes Fizz →

Your First Fuelling Kit

If you're just starting out, here's a simple setup that covers the basics:

For sessions under 90 minutes:

• Water
• Endurolytes capsules or Endurolytes Fizz tablet

For sessions 90 minutes to 3 hours:

• 1–2 Hammer Gels per hour
• Water
• Endurolytes capsules

For sessions over 3 hours:

• Hammer Gel for portable calories
• Perpetuem for sustained longer-duration fuel
• Endurolytes for electrolyte replacement
• Water

Shop Hammer Gel →
Shop Endurolytes →
Shop Perpetuem →

Common Mistakes to Avoid

Fuelling too late. By the time you feel hungry or fatigued, your performance has already dropped. Start taking on fuel early and maintain a regular schedule.

Taking too much at once. Large amounts of carbohydrate consumed in one go are harder to digest. Small, regular amounts work better.

Skipping electrolytes. Particularly in warm weather or during long events, electrolyte depletion is a major cause of cramping and fatigue.

Trying new products on race day. Always practise your nutrition strategy in training first. Race day is not the time to experiment.

Drinking too much plain water. Overhydration without electrolyte replacement can dilute blood sodium levels. Drink to thirst and include electrolytes.

Race Day vs Training Day Fuelling

Training is where you develop your fuelling strategy. Use your long sessions to test different products, timing and quantities so that by race day you have a plan that works for your body.

On race day, stick to what you know. Nerves, heat and effort levels will all be higher than in training, so a familiar, tested nutrition plan is your best asset.

A good rule of thumb: if it works in training, it will work on race day. If you haven't tested it in training, don't use it in a race.

Explore Our Full Range of Guides

• Hammer Gel Fueling Guide → — dosing, timing and race-day strategy
• Fuelling Guidelines → — Hammer Nutrition's complete fuelling framework
• About Hammer Nutrition → — 39 years of endurance nutrition