Fuel, Hydrate, Finish: Lessons from the Marathon That Nearly Broke Me

I’ve always loved running—it was my go-to for stress relief and movement until CrossFit took center stage in 2016. When COVID hit and gyms shut down, I rediscovered my love for running, eventually completing several half-marathons and setting my sights on a full marathon. My first attempt at the BMW Dallas Marathon in 2024 ended at mile 18 due to intense hip pain. It was crushing, but it only fueled my determination. I hired a coach, ramped up my training to 40-mile weeks, and signed up for the Cowtown Marathon. This time, I was ready—or so I thought.

Despite the miles and preparation, things unraveled around mile 20. I hit the dreaded wall—nausea, dizziness, and zero energy. I had planned to take in 60g of carbs per hour but hadn’t practiced that amount during training. My body rejected the fuel when I needed it most. A chance pep talk from another runner pulled me through the final stretch, and I crossed the finish line in tears—relieved, proud, and wiser.

Where It All Fell Apart (And Why)

Things were smooth until mile 20. Then came the dreaded “bonk”:

• Nausea

• Dizziness

• Empty energy tanks

I had planned to consume 60g of carbs per hour—but never practiced this during training. My body rejected it. My stomach revolted. And I almost quit.

Only a random pep talk from a fellow runner helped me push through those last two miles.

Lesson learned: Nutrition and hydration aren’t just important—they’re everything.

Fueling and Hydration for Performance

Whether you're running a marathon or tackling a CrossFit WOD, what you eat—and drink—matters.

1. Carbohydrates: Your Primary Fuel Source

Carbs are what your muscles crave during high-intensity or long-duration activity. Without them, your performance suffers. During long efforts, your body relies on stored glycogen and circulating glucose to power your muscles. If glycogen runs out, your performance suffers and fatigue sets in—commonly known as "hitting the wall."

✅ Goal: 30–60g carbs per hour during long workouts or races. 

🍌 Try: Energy gels, bananas, chews, or sports drinks with carbs.

🧠 Pro Tip: Practice your fueling strategy during training. If your gut isn’t used to digesting that much sugar while moving, race day will be rough.

2. Hydration and Electrolytes: Don’t Just Sip Water

Sweating means losing more than just water—you’re also losing electrolytes (sodium, potassium, magnesium). Water regulates body temperature and supports muscle function. However, during prolonged or intense activity, you lose not just water but electrolytes—especially sodium—through sweat. Inadequate hydration and low electrolyte levels can result in cramping, dizziness, and early fatigue.

✅ Goal:

• Hydrate consistently, not just when thirsty

• Use an electrolyte drink or tabs if working out longer than an hour

• Rehydrate post-race with 16–24 oz per pound lost

💧 Try: Nuun, LMNT, Liquid IV, Skratch Labs

3. Pre, During, and Post-Workout Nutrition

Before Exercise

• Eat 2–3 hours before your workout

• Include 40–60g carbs and some protein 🥜 Example: Toast with peanut butter + banana

During Exercise (if >90 mins)

• 30–60g carbs per hour

• Electrolytes in your fluids 🥤 Example: Sports drink + energy chews

After Exercise

• Replenish within 30–60 minutes

• 60g carbs + 30g protein 🍽️ Example: Chicken and rice, or a protein shake with fruit

• Don’t forget to rehydrate with electrolytes

Final Thoughts: Train Your Gut, Not Just Your Legs

Fueling and hydration strategies are just as trainable as your endurance or strength. If you want to finish strong—and avoid hitting the wall—you need to practice what you eat and drink, when, and how much.  Use long training days to test the exact products and quantities you’ll use on race day.

Trust me: it makes all the difference.

References & Resources

• Thomas, D.T., Erdman, K.A., & Burke, L.M. (2016). Nutrition and Athletic Performance.

• Sawka, M.N. et al. (2007). Exercise and Fluid Replacement. 

• Jeukendrup, A.E. (2014). A Step Towards Personalized Sports Nutrition. Sports Medicine

• Ivy, J.L. (2004). Regulation of Muscle Glycogen Repletion, Muscle Protein Synthesis and Repair Following Exercise. Current Sports Medicine Reports

• Institute of Medicine (2004). DRIs for Electrolytes and Water.

• Perez Castillo, Íñigo & Williams, Jennifer & Lopez Chicharro, Jose & Mihic, Niko & Rueda, R. & Bouzamondo, Hakim & Horswill, Craig. (2023). Compositional Aspects of Beverages Designed to Promote Hydration Before, During, and After Exercise: Concepts Revisited. (Image)