Race Fueling 101


I’ve been competing in endurance races for over 3 years.  I’m an amateur compared to many endurance athletes.  But I am an expert when it comes to fueling.  My stomach problems have made it difficult to find race nutrition that works for me.  But my loss is your win.  Olivia is less than a month away from her first marathon and has been experiencing some fueling issues.  When she came to me for advise about what to eat during a race, I figured I’d make a post of it.  This is what works for me.  Everyone’s bodies are different so don’t be discouraged if some of my suggestions don’t work for you.  It’s all about experimenting to see what works for your body.  

Hydration. Hydrating is an absolute necessity if you want to perform well in your race.  To avoid post-race IVs, follow these steps.  In general, it is recommended that you keep your fluid intake between 16 and 30 ounces per hour.  30 ounces is on the very high end and 16 ounces is the minimum.  You obviously don’t want to take in all of your fluids at once (holy sloshing), so I recommend drinking 4-8 ounces of fluid every 15-20 minutes.  I personally can’t tolerate large amounts of liquid when I run, so I drink small amounts frequently (4 ounces every 15 minutes). Adjust your hydration according to temperature.  If it’s a hot day, you need to drink more.  Common sense.

Fuel. During an endurance race, the general rule of thumb is that you should consume between 30 and 60 grams of carb per hour.  (This equates to roughly between 200 and 300 calories).  The amount of fuel you need is going to depend on your weight and what your body can tolerate.  

The two most common types of fuel are gels and chews.  Most energy gels contain about 25 grams of carb (100 calories).  Most energy chews contain about 5-8 grams of carb per chew (although different brands vary).  I find it difficult to take in a lot of fuel at once so I like to break it up into 15 or 30 minute increments.  During most of my races, I try to eat ~12 grams of carbs (50 calories) every 15 minutes.  It’s smart to follow your gel or chew with water. 

Sports drinks can also provide you with carbohydrates.  Your typical sports drink is going to contain 15 grams of carb per 8 ounces (or 7.5 g of carb per 4 ounces).  I wouldn’t recommend only using liquid fuel (especially during a run), but you can definitely get some of your carbohydrates and calories from sports drinks.  Don’t chase your gels with sports drinks, though.  Your GI system will hate you.

Electrolytes.  Eating and drinking will probably cover your electrolyte needs, but it’s still good to be educated.  Electrolyte intake varies greatly from person to person and depends on the conditions you’re racing in BUT most people should consume 400-600 mg of sodium per hour.  Gels and chews will provide you with some sodium, but primarily your sodium is going to come from sports drinks or electrolyte tabs/pills.  Most sports drinks contain about 200 mg sodium per 8 ounces.  There’s a ton of options for sodium/electrolyte intake so experiment and listen to your body.  

Check back tomorrow to learn my absolute favorite types of fuel and why I like them!

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