CALORIC INTAKE

Fuel Smarter for Better Endurance Performance

Endurance athletes rely on three key fuel sources: carbohydrates, protein and fat. The trick is using the right fuel, at the right time, in the right amount. Get that wrong and even the strongest legs can turn into soggy breadsticks halfway through a race.

Why Complex Carbs Win

Not all carbs are equal. Many sports drinks are packed with simple sugars like glucose, fructose and sucrose. These can sit heavily in the stomach, cause bloating and energy crashes, and often force athletes to drink far too much fluid just to get enough calories.

Complex carbohydrates, especially maltodextrin, are far easier to absorb and can deliver more energy without upsetting digestion. They also avoid the dramatic blood sugar spikes and crashes linked to sugary drinks.

In simple terms:

• Simple sugars = quick spike, quick crash
• Complex carbs = steadier energy and happier stomach

That’s why fuels based on maltodextrin, such as Perpetuem, HEED and Hammer Gel, work so well during endurance exercise.

Don’t Overfuel

A common mistake is trying to replace every calorie burned. Your body already carries massive fat stores for energy, especially during longer sessions.

Trying to cram in too many calories can:

• Slow digestion
• Cause cramps and bloating
• Reduce fat burning efficiency

For most athletes, around 120 -180 calories per hour is plenty.

When Protein Matters

Once exercise goes beyond roughly 2 hours, protein becomes important. Without it, your body starts breaking down muscle tissue for fuel — not ideal when you still have miles to go.

A carb-to-protein mix helps:

• Reduce muscle breakdown
• Lower fatigue
• Support recovery
• Improve long-duration performance

Soy protein is particularly effective during endurance events because it digests well and produces less fatigue-related ammonia than whey.

The “Grey Area” Races

Events lasting 2–3 hours sit in a tricky middle ground.

For harder efforts, hot weather or hilly terrain, simpler fuels like HEED or Hammer Gel are often easier to digest.

For longer, steadier efforts over 3 hours, carb-plus-protein fuels such as Perpetuem or Sustained Energy usually work better.

Key Takeaways

• Use complex carbs over simple sugars
• Avoid overloading calories
• Add protein after 2 hours of exercise
• Train your nutrition strategy just like your fitness
• Adjust intake based on heat, intensity and terrain

The best fuelling plan is always personal. What works brilliantly for one athlete may leave another hunting for the nearest hedge at mile 40. Test everything in training first.