Overheard at the Aid Station: What Ultrarunners Get Wrong

Whether you’re pacing for a friend or toeing the line yourself, if you’re running an ultra (or just training), nutrition matters. I spent a weekend crewing at a 100k and heard some wild stuff at the aid stations - from runners, pacers, and crew alike. Let’s break down the biggest mistakes I overheard - and what you can do instead to avoid them.

Training Fasted

Despite what the keto crowd wants you to believe, there is no evidence that the increased fat oxidation that accompanies fasted training actually translates into improved performance. There is evidence that fasted training increases your risk of injury.

What to do instead: Eat before you train! If this is new to you, start small. Half a banana, an applesauce pouch, or a glass of your favorite sports drink are all great starting points to build the habit. Gradually build up to about 40-80 grams of carbs (Not sure how to do this? Check out this Instagram post with 7 examples.)

Only Drinking Water on Course

Research on sodium replacement is still in its infancy, but if it’s hot out and/or you are a heavy or salty sweater and/or you’re running for longer than about 3-4 hours, you probably need sodium. Sodium helps your body retain water (to increase hydration), may actually make you thirsty to encourage drinking, and may help prevent hyponatremia. The jury is still out on whether or not sodium plays a role in performance.

What to do instead: Sodium needs are highly individual based on your unique sweat rate and composition, but a good starting point to avoid hyponatremia is to aim for at least 400 mg of sodium per liter of fluid. Sports drinks, like Gatorade, Skratch, or Tailwind make it easy to consume sodium (and as an added benefit, they also provide carbs). Salt chews, salty snacks (like chips or broth), and high sodium gels can all help you meet your sodium needs.

Not Peeing for 12 Hours

Y’all, 12 hours is too long to go without peeing. Everyone’s body is different, but a healthy, hydrated bladder should empty about every 2-4 hours. Much longer than that is a sign of dehydration.

What to do instead: You can’t force a pee, but you can stay hydrated! A good rule of thumb is to aim for about 300-600 mL of fluid per hour... and adjust upwards if your pee is infrequent and/or apple juice colored or darker. In case you missed it, check out Thriving in the Heat for a deep dive on hydration (as well as training strategies to feel better this summer).

Literally Not Eating Anything Until Mile 25 of a 50k

Yikes. Your body only has enough carb storage capacity to get you through about 90 minutes at marathon pace. While you can break down fat stores (and protein stores, AKA muscle) to fuel your engine, it is far from optimal - especially if your race has any steep climbs that require a harder effort. Research consistently shows that adequately fueling your races (and training) results in improved performance… as well as reduced risk of injury, better energy, and less yucky feeling (not a scientific term).

What to do instead: Eat early, eat often. For most runners, 70-90 grams of carbs per hour is a good target for a 50k. This can come from gels, sports drinks, and solid foods - and I recommend choosing a variety of flavors and textures, especially if you plan to be out for a while. Practice this in training so there are no surprises on race day.

Drinking a Beer Before Pacing

Of all the things out there, this may not be the worst… but in 95 degree weather, it wouldn’t be my first choice. Alcohol can dehydrate you and make it harder to regulate temperature, increasing risk of heat stroke.

What to do instead: Save the beer for post-race and choose water or sports drink instead.

The Bottom Line

Even the most dedicated of runners miss the mark on fueling. The result? Poor performance, low energy, and GI problems. Training is only half the equation.

You don’t have to do it on your own. Whether you’re training for your first 50k or your 50th 100 miler, I can help you learn how to fuel your body to feel and perform your best. Ready to learn more? Fill out an application today.