Most first time marathoners don’t hit the wall at mile 20. They set it up in the opening miles. Starting too fast and delaying fuel creates a chain reaction that no level of fitness can fix. By the time things fall apart, the real mistake is already far behind you.
Pacing and Fuelling Are the Same Problem
Pacing and fuelling are often treated as separate parts of race strategy. In reality, they’re tightly linked. Go out too fast and your body relies more heavily on stored carbohydrates. Burn through those too quickly and you’ll struggle to replace them, especially since higher intensity reduces how well your gut absorbs fuel. The result? You fade earlier and you fade harder. Most runners will slow down in the second half of a marathon. That’s normal. The goal isn’t to avoid slowing down entirely, it’s to minimise it. And that comes down to managing both pace AND fuel from the very start.
Fuelling Strategy: Start Early, Stay Consistent
A good fuelling plan isn’t complicated, but it does require discipline.
1. Don’t wait until you feel tired
If you’re waiting for a signal, you’re already behind. Energy levels drop before hunger kicks in.
2. Start fuelling early
Begin around mile 2–3, even though you feel fresh.
3. Stay consistent
Aim to take in fuel every 20–35 minutes rather than in large, infrequent doses.
4. Hit your targets
Aim for 60–90g of carbohydrates per hour. Most runners significantly underfuel, often without realising it. A simple, structured plan helps avoid this.
5. Practice in training
Your gut is trainable. Use long runs to build tolerance, refine timing, and gain confidence in your plan.
Choosing Your Fuel
During a marathon, simple carbohydrates are your best option, they’re quick to digest and easy to use. This is why most runners rely on gels, chews or sports drinks to meet their hourly targets. If you’re new to fuelling, start at the lower end of the range and gradually build up in training.Combining different carbohydrate sources (such as glucose and fructose) can also help increase how much you can absorb per hour, something that becomes more important as race intensity rises.
Caffeine: Optional, but Effective
Caffeine can be a useful tool, particularly in the later stages of the race when fatigue builds.
- Before the race: A moderate dose 45–60 minutes before the start may help reduce perceived effort
- Mid-race: A second dose around halfway can help during the toughest miles
That said, caffeine isn’t essential and it’s not risk-free. It can cause stomach issues under race conditions, so it should only be used if you’ve already tested it in training.
Common Mistakes to Avoid
Even well prepared runners fall into the same traps:
- Starting too fast because of adrenaline
- Waiting too long to begin fuelling
- Trying new nutrition on race day
- Treating pacing and fuelling as separate strategies
Avoiding these mistakes is often more important than chasing marginal gains.
The Bottom Line.
1. Start slower than you think you should.
2. Fuel before you feel like you need to.
3. Stay consistent from beginning to end.
Do that, and the final 10K becomes something you manage, not something you survive.