Fueling For the Marathon on a Paleo Diet

Fueling for long distance events on a high fat Paleo style diet allows you burn fat more efficiently, and can help you steer clear of intestinal distress caused by ingesting too many sugary carbs before and during a race. If you’ve been suffering from runner’s diarrhea, gas, bloating or are just looking for a way to fuel your body more efficiently, you may want to experiment with a higher fat diet. I’ve  run two sub-3hours marathons this way, and wouldn’t go back to all the pasta, bread and copious shots of GU.

Combating GI Distress

I recently ran a 2:57 at Twin Cities Marathon. During the race I fueled with just 3 gels. The previous year, I ran a 2:55, while only taking 2 gels and some diluted sports drink along the way.I used to have problems ingesting the typical runner’s foods.  All the sugar and excess carbs would cause an upset stomach, forcing me to spend precious time in a porta-potty with runner’s diarrhea. 

Fortunately, I’ve been able to combat the problem naturally by using a higher fat Paleo style diet. Rather than having to constantly take lots of gels for energy, I can use body fat as fuel and mitigate pits stops. 

Why a higher fat diet may work for you

The beauty of a higher fat diet for an endurance athlete is that it forces your body to learn to use fat as your primary fuel source. This helps spare limited glycogen supplies for intense efforts, such as running uphill or a strong finishing kick.

Why take any fuel during a race?

As the distance you run gets longer, your brain, which only cares about survival and not setting a new Personal Record, begins sending signals to your body encouraging you to slow down. We call this fatigue. By providing your brain and body some form sustenance, you are sending signals to your brain that it is okay to keep pushing the pace.

Convenience of using supplies on the race course

Ideally I’d like to use the same product during races as I do in training, which is 3Fuel. I’ve been using it during all of my training runs of up to 26 miles. It works perfectly with my higher fat diet because it doesn’t spike blood sugar and lets me continue to burn fat as a primary fuel source. 

It also helps with the more intense efforts by including some slow releasing carbs in the mix. It’s made with a slow releasing starch, coconut milk, and grass fed whey protein. I’ve found it to be gentle on the stomach as well. 

The problem is, they don’t have it at the aid stations during marathons and I don’t like carrying bottles with me during a race. Using the provided gels and sports drink on the course is incredibly convenient, and if you do it right, you can make it work. I shoot for around 1 gel per hour. I recommend taking the gel very slowly. By taking the gel slowly over a couple of miles, you reduce the glycemic load and you won’t get any major blood sugar spikes. 

Listen to your body

When you get to the aid stations, listen to your body. If you’re not thirsty, bypass the aid station. For me, if I’ve just taken a gel over the previous mile or two, I go for water. If it’s been a while since taking a gel, I might go for a few ounces of the diluted sports drink.

Do what works for you

Everything I’ve written so far is just what works for me. You should experiment for yourself. For example, if your are insulin resistant (pre-diabetic),  taking a gel or sports drink isn’t going to help you. Your body doesn’t respond well to carbs anyway, so the carbs you take aren’t going to be used as fuel by your muscles. Rather, they will just be stored as fat. 

What I eat

Day before race (more carbs than usual):


Smoothie: 1.5 Banana, 1/2 cup coconut milk, 3/4 cup full fat Kefir, spinach, berries, protein powder


Mashed potatoes loaded w/ butter & sour cream

Cup of full fat yogurt w/ berries


Mashed potatoes loaded w/ butter & sour cream
4 ounces liver cooked in grass fed ghee

Morning of race (3 hours before):

Smoothie: 1 scoop 3fuel, 1/2 cup coconut milk, 1.5 bananas

During race:

1 gel per hour and sports drink or water as needed

5 thoughts on “Fueling For the Marathon on a Paleo Diet

  1. Hi,I follow a Paleo-lowcarb style diet.I ran a 3:52 Marathon last Sunday. I think I had GI distress with gels. My plan was one gel each 7Km. After the third, my stomach was telling me not to take anyone more. Maybe it was because I did not drink enough water with the gels. How much water should I drink with each gel?Adolfo


    1. Nice job at your marathon Adolfo! They recommend taking them with 8 ounces of water, but I’ve found that I don’t need that much. I just take water to thirst. In Tim Noakes’ book Waterlogged; he says your body will simply add the appropriate amount of water to your stomach to digest properly.


  2. What gels do you all use? I’ve used a few different kinds, but being that they’re loaded with sugar, I wasn’t sure how this worked for a paleo diet?


  3. Would you mind sharing what gels you use? Would love to know what worked for you, I know it’s different for everyone!


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