Some obstacle course racers will tell you that their failsafe race-day fuel is nothing but a guzzle of water and a gulp of air. (These folks are of the mind that an empty stomach makes them faster, lighter, more agile, and aggressive on the course.) Though the desire to eat a pre-race meal can be a highly individual matter, there’s no getting around the fact that for a taxing event that can go on for over an hour, you’re going need something in your stomach to pull you through. 

Fortunately, properly fueling up with food (and drink) on race day is a pretty straightforward affair — just make sure you have a mix of carbs and protein.

“Carbohydrates give your body and brain energy, and protein helps sustain that energy,” Jessica Crandall Snyder, RDN, CDE, NASM, a registered dietitian and trainer at VitalRD.com, says.

Related: How to Choose the Right Carbs for the Right Race

Snyder, who has run a few Spartan races herself, says pairing carbohydrates and protein has recently been shown to provide better long-term energy for events like Spartan races. Start with a breakfast that’s around 15 to 30 grams of carbohydrates and at least 5 to 15 grams of protein, Snyder says. Get your carbs from fruits or starchy vegetables like potatoes. Protein typically comes in animal products such as meats, eggs, cheese, and dairy. (Greek yogurt and ricotta cheese are good choices.)

How to Hydrate Before a Race

Proper hydration is also a key component of your race-day fuel. Even a 1- to 2-percent decrease in your hydration levels can hinder performance, studies show.

“I encourage water as a primary source of hydration,” Snyder says. “However, if you’re going to be doing more than 60 minutes of activity, it’s important to think about electrolyte and carbohydrate replacement. Lean on alternative fuel sources such as an electrolyte/carbohydrate beverages or coconut water.”

Drinking plenty of water pre-race is essential, but make sure you hydrate well the night before, too. Nix the alcohol and go easy on caffeine, which can mess with your stomach.

Related: This Is Why Hydration Is More Important Than You Think

Whatever you decide to eat and drink, don’t wait until race day to see how it works for you.

“I have tried so many things that either didn’t agree with my stomach or didn’t really fuel me well enough, so be sure to test drive your meal," Snyder says.

Snyder prefers a sweet potato hash with eggs, black beans, and diced tomatoes, or an almond butter, banana, and Greek yogurt bowl before her Spartan races. (The beans might not sit well with you — another example of how crucial test driving your fuel is.) We asked a few other die-hard Spartan racers for their race-day fuel, and got loads of ideas. If you're looking to hit a new PR or just switching up your fueling strategy this season, take a look and find inspiration for your next performance-boosting meal.

Spartan Racers' Race-Day Nutrition Picks for Long Events

• If it’s a long race, oatmeal with peanut butter, nuts, and raisins, and a boiled egg and a banana. — Isaura Zavala, Chicago, Illinois
• An oat pancake … Just oatmeal, three eggs, and a little syrup in it. It works well. — Tanya Stevens Pence, Hartland, Michigan
• Waffle, oatmeal, and sometimes a bagel. Just before loading in the box, I’ll have a banana and a 32-ounce Powerade with Pedialyte powder. — Matthew Brian Smith, Monroe, North Carolina
• One egg with an extra egg white over easy, fried with cheese and avocado on wheat bread. — Ronnie Bustos, Madera, California
• Three hours before the race, I’ll have my oatmeal concoction, which includes oats, ground flax seeds, blueberries, a scoop of protein powder, cinnamon, and almond milk. Then an hour before start time, a banana with Gatorade. — Wayne Macio 
• Overnight oats in a Mason jar, cold or heated up. Oats, almond milk, a tablespoon of peanut butter, and maple syrup topped with sliced banana., plus a cup of coffee. — Lisa Campbell, Ottawa, Ontario
• I typically make some kind of muffin that includes, oats, Greek yogurt, and berries. — Sara Stoner-Delatorre, San Diego, California
• For Supers, it’s a piece of toast with peanut butter. Two hours before the race, I’ll have an apple, and about 30 minutes before, a pre-workout drink. — Aaron Hammer
• A bagel with peanut butter, egg whites, and a banana! I eat half the bagel and the eggs early, and then the other half and the banana 1 to 2 hours before start time. — Logan Marcocci, Owego, New York