How to Fuel a Marathon
Marathon fuelling is mostly about starting early and staying consistent through the race, rather than finding a single perfect product. Waiting until you feel low on energy is the most common mistake, since by then you're already behind and hitting the wall becomes considerably more likely.
Why the marathon is different
Glycogen stores generally last somewhere around 90 minutes to two hours of continuous running for most people, well short of the time most recreational runners spend covering marathon distance. That gap is exactly why fuelling during the race matters so much more here than for shorter distances, where finishing before glycogen runs low is much more realistic.
A practical timing approach
A commonly used starting point among recreational marathoners is a gel or equivalent quick carbohydrate source roughly every 40 to 60 minutes, starting earlier than feels necessary, often from around 45 minutes into the race. This is a general starting framework, not a fixed rule, and your own tolerance and training will refine it.
- Start fuelling earlier than feels necessary, generally by 45 minutes to an hour in
- Aim for roughly one gel or equivalent every 40 to 60 minutes as a starting point
- Pair gels with water rather than taking them completely dry where possible
- Adjust the exact timing and product based on what you've practiced in training
Gels, chews, and other options
Gels are the most common choice because they're compact and quick to consume, but chews, sports drinks, and even familiar solid foods work for some runners, particularly on longer training runs. The right choice is largely about what your stomach tolerates and what you'll actually remember to use consistently, not which option is theoretically fastest to digest.
Test everything in training first
Whatever fuelling plan you land on, test the exact product, brand, and flavour on at least one or two long training runs before race day. Different products can sit very differently, and marathon day is not the time to discover that a particular gel doesn't agree with your stomach.
Hydration alongside fuelling
Fuelling and hydration work together, and getting one right while ignoring the other still leaves you vulnerable to a rough second half. See hydration planning for race day for how much to drink and how to adjust for heat, and carb loading explained for how pre-race eating sets up the fuel you're working with on the day.
Know what's on the course
Some marathons offer gels or sports drinks at aid stations, others only offer water, and spacing between stations varies by event. Check your specific race's category page for aid station details rather than assuming, since planning around the wrong assumption can leave you short on fuel or water later in the race.
Browse upcoming marathon events and check aid station details before you plan your fuelling.
Browse eventsMy honest read, from the aid station questions we see around marathon listings specifically, is that a meaningful share of first-time marathoners seem to assume gels will be available on course when many events actually only provide water and electrolyte drinks. I can't put a precise number on how common that assumption is, but it comes up often enough in pre-race messages to be worth flagging. Checking your specific event's aid station details on the category page is a small step that avoids a genuinely bad surprise mid-race.
Frequently asked questions
When should I start fuelling during a marathon?
Earlier than feels necessary, generally from around 45 minutes to an hour into the race, rather than waiting until you feel low on energy.
How often should I take a gel during a marathon?
Roughly every 40 to 60 minutes is a common starting point for many recreational runners, though your own tolerance and training should refine the exact timing.
Are gels better than chews or sports drinks?
No single option is universally better; it comes down to what your stomach tolerates and what you'll consistently remember to use during a race.
Should I rely on aid stations for fuel during a marathon?
Only if you've confirmed your specific event provides gels or sports drinks on course. Many races only offer water, so it's worth checking the category page in advance.