11 Marathon Fueling Tips for a Faster (And More Enjoyable) Race

11 Marathon Fueling Tips for a Faster (And More Enjoyable) Race

Mark Kennedy
Founder of None to Run
June 20, 2023


fueling for marathon


The marathon is a tricky distance to run for a couple of main reasons.

Firstly, it’s a long way and places huge demands on the body – both physically and mentally.

Secondly, your body has limited glycogen stores that only last for a couple of hours. This poses a problem for most recreational runners as we’re out on the course for 3, 4 or more hours.

Fueling then, becomes not only a necessity, but an aspect of marathon training that simply cannot be ignored.

Research shows that optimizing your hydration and carbohydrate needs can improve your marathon performance from 2-20% – depending on your current level of fitness and running experience.

While 2% does not sound like much, it equates to 2 and a half minutes for a 2:15 marathoner. Those 2 and a half minutes are the difference between qualifying for the marathon World Championships and watching it on TV.

For a 4 hour marathoner, a 5% improvement sheds 12-minutes from your time, placing you in the “sub 3:50” club.

So if you really want to run a marathon to your potential and not just “get by” or “grind it out”, you must make fueling a priority.

Here are 11 different actionable tips to help you fuel for your next marathon:

Test different types of fuels.

🍬 The best fuel is a combination of glucose and fructose.

📜 The rule of 15.

🏫 Practice, practice, practice.

🧪 Experiment with caffeine.

🥤 Squeeze your cup.

🗺️ Study the course.

⏱️ Start fueling early.

🎒 You might have to carry your own fuel.

🥵 Hydration needs are weather dependent.

🥕 Train occasionally (not race) in a fasted state.

1. Test different types of fuels.

Runners have different tastes. Some people can chug back energy gels like they are shots of water. Others, like me, struggle with the consistency and texture of energy gels.

Some runners can’t fathom chewing something while running. Some don’t have an issue with it.

You need to find the type fuel that works for you from both a taste and texture standpoint.  Go to you local running shop or favorite online running store and order a bunch of different gels, chews, jellybeans and sports drinks.

Within your order, be sure to get the types of fuel (gels/chews and sports drink) that will be offered in your race. This will save you from carrying your own fuel during the race (which isn’t a big deal if you need to) if they agree with you.

Try them all on your training runs and see what you like.

Get 10% all sports gels and chew at Running Warehouse – use the coupon code “healthy10” at checkout. 

2. The best fuel is a combination of glucose and fructose.

Current research shows that using fuels that contain a combination of glucose and fructose is optimal. Glucose and fructose are carried across the intestinal wall to the bloodstream by two different transporters.

If you’re consuming a glucose-only fuel, the amount of energy that enters the bloodstream will be limited.

By taking in a mix of glucose and fructose, you take advantage of additional transporters that will move fructose into the bloodstream as well.

Most gels and chews these days contain a combination of both. Often you will see maltodextrin as an ingredient, which is glucose as well.

Check the labels to see what you’re consuming.

Absorption of different types of carbohydrate.


Source: http://www.gssiweb.org/Article/sse-108-multiple-transportable-carbohydrates-and-their-benefits
                                                                                                                                                                                                                       Source: http://www.gssiweb.org/Article/sse-108-multiple-transportable-carbohydrates-and-their-benefits                                


3. The Rule of 15.

Most marathoners know they need to fuel, but don’t know how much.

In a recent podcast interview I did with Dr. Trent Stellingwerff, he provided a simple way remember how much fuel (carbohydrates) you require for a marathon.

Enter the Rule of 15.

15 grams of carbohydrate every 15 minutes or 60 grams of carbs per hour – that’s what you should aim for.

Of course, some runners will be able to handle this amount of carbohydrate, others will not and may need to start at 30 grams and progress up from there.

Most energy gels provide approximately 25 grams of carbohydrate. And don’t forget, you can obtain some of these carbohydrates form a sports drink.

So, to get 60 grams of carbohydrate in an hour, you would need to consume two gels and 2.6 ounces of Gatorade.

4. Practice, practice, practice.

Fueling for a marathon is not something you should wing, especially if you care at all about your time and having an enjoyable race experience.

  • Practice the amount of fuel your take in. Some runners will be able to handle more than others. Start practicing at 30 grams (about 1 gel) of carbs per hour and work your way up.
  • Practice taking fuel from your belt while actually running.
  • Practice your fueling strategy on 5-6 long runs and ensure you do so at goal (or close to your goal) marathon pace. The physical and mental demands of running at your goal pace will provide the best simulation to what you’ll encounter on race day. Practicing your fueling on an easy 10 km run just is not the same.
  • Document how much fuel you consumed on each run and how you felt.

5. Experiment with caffeine.

Ever wondered why caffeine is often found in many pain medications?

Caffeine has been shown to block the processing of pain signals on the central nervous system. In a marathon, caffeine’s effects will help you focus more and blocks some of the pain associated with the efforts related to running 42.2 kilometers.

Aim to take in 100 to 200 milligrams of caffeine about 30-60 minutes prior to your race. During the race, 25 or 50 milligrams per hour will provide a top-up and provide benefits later in the race when you really need it.

For reference, a tall Americano from Starbucks provides about 150 milligrams of caffeine.

Most of the major energy gels brands offer gels and chews with caffeine. Clif Bloks (Black Cherry) contains 50 milligrams of caffeine per serving (3 bloks).

6. Squeeze your cup.

Drinking from those paper cups at aid stations without stopping and spilling more water on your face than gets into your mouth is difficult.

Simple tip here and it may seem like common sense, but not everyone does it.

When you grab a cup of water or sport drink from the aid station, slightly squeeze the top of the cup to make the top opening smaller (like a water bottle). Now drink through the narrow opening.

You’ll get much more fluid into you and less on your shirt.

7. Study the race course.

You don’t want any surprises on race day.

Study the race course and know exactly where every aid station is and what type of fuel they’ll offer (brand of gels and sports drink).

Organize with a friend or family member to be at a specific spot (preferably around the 30 km mark) on the marathon race course and give them some backup gels and sports drink.

You may not need the extra fuel, but it’s reassuring to know it will be there should you accidentally drop some of the fuel you are carrying or just need an extra boost.

8. Start fueling early.

Don’t wait until you’re starting to feel tired before you fuel. Start fueling as early as 15 minutes into the race in order to hit the optimal amount of 60 grams of carbohydrate per hour.

9. You might have to carry your own fuel (and that’s okay).

If you’re not going to rely on the fuel offered on the marathon course, you will need to carry your own. There are lots of different belts and waste packs available to get the job done. The Jurek EndureJurek Essential and Spibelt are great options to check out.

10. Hydration needs are weather dependent.

The weather largely dictates how much fluid you should take in during your marathon. Running a marathon in Hawaii for example, will require much more fluid intake than an early spring marathon in Toronto.

Try to let thirst be your guide, but a lack of thirst on a cool does not mean you require any less carbohydrates. Even on cool days, a marathon runner will have fueling and carbohydrate needs – you just won’t be as thirsty.

Using sports drinks will help you meet both your hydration and carbohydrate needs.

11. Train occasionally (not race) in a fasted state.

Once in a while, go for your long run (ideally in the morning) in a fasted state.

The night prior, have your dinner and go to bed as you normally would.

In the morning, have a glass of water (and a coffee if you like) and then head out for your run.

Why? The glycogen stores in your liver will be somewhat depleted and your body will be forced to utilize more fat as fuel. As you get better at this, you will better be able to hold your marathon pace without depleting your glycogen stores like you would have.

Also, training your body to better use fat as a fuel source late in a race, when you’re really pushing to maintain your pace, will also provide psychological benefits.

The last 10 kilometers are going to be tough no matter what.

Because you’ve had the unpleasant experience of running long with no fuel, you’ll be sure to feel much better on race day when you’ve had breakfast and have been fueling for the past 32 kilometers.

Further Resources



Dr. Trent Stellingwerff: A Blueprint for Fueling the Marathon

 Gear (fuel belts, gels, chews, etc.)


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