Why Do Half Marathon Runners Need Sports Nutrition?

Blog post contributed by the Official Energy Chew sponsor, Gu Energy Labs.


Through training, we grow stronger, get faster, and learn how to endure more.

By eating the right nutrients, in the right amounts, at the right times, we build our muscles, mend our bodies, and optimize our training efforts. While athletes train hard to prepare for races like the Berkeley Half Marathon, they also need proper fuel to make sure they feel good and their performance doesn’t suffer on race day.

When you’re out running for miles on end, your muscles consume their glycogen stores after only an hour and a half. Your body needs fuel in the form of calories to keep going to avoid the dreaded bonk. When you run, blood is diverted away from your digestive tract to power your muscles, so you need something that is easily digestible and can be converted to energy quickly. Sports nutrition products like energy gels, chews, and drink mixes provide fast-acting energy so you can fuel quickly without stomach issues, allowing you to keep pushing hard. Along with sufficient hydration and electrolytes, the type of food you eat is crucial. In long races like the Berkeley Half Marathon, proper race fuel can be the difference maker between getting to the finish line feeling good or struggling through the last five miles. 

Fueling is not just for race day. The fuel you eat during training sessions is equally important. At GU we like to say “Eating is Training” as it’s a mantra for optimizing athlete’s everyday diet. It means tailoring your nutrition intake to meet the demands of your training cycle with planned and purposeful fueling. Eating is training, is a holistic approach to nutrition with a focus on performance and recovery.

Check out GU’s Pinnacle Podcast episode for more on the “Eating is Training” philosophy.



Race Day Nutrition 101 — The Basics

You’ve invested energy, money, and a whole lot of time to get to the start line, so make sure to set yourself up for success with a fueling and hydration plan. There are three basic aspects to creating a nutrition plan, energy, hydration and recovery. Yes, everyone is different and responds differently to what they eat and drink, but here are a few rules of thumb we recommend following to keep you performing and feeling good on race day.






Energy — Food is Fuel!

  • Rule of Thumb #1: Consume 100-200 calories per hour while running. That’s the magic range that will work for most people. While it’s possible to train your body to absorb more than 300 calories per hour, if you haven’t practiced before race day, we recommend staying within this range. Start consuming in your first hour of running since you are bound to go into a calorie deficit in a race like the Biofreeze Berkeley Half Marathon.

Hydration — The Key to Powerful Performance 

  • Rule of Thumb #2: Hydrate along the way by drinking between 16-30 oz of fluids every hour. Staying hydrated is one of the easiest ways to make sure your body is performing at its potential. When you’re dehydrated, your power output goes down. Don’t waste your run and keep the fluids flowing!
  • Rule of Thumb #3: You need electrolytes to absorb fluids — 300-700 mg of sodium per hour. Plain water does not absorb as efficiently as water with electrolytes, so make sure you’re getting enough salt to help you hold that hydration. We supplement sodium in all GU energy products to make hydrating easier for you. Just sip some water after a gel, chew or Stroopwafel to nail your hydration plan.

Recovery – Don’t Waste Your Workout

  • Rule of Thumb #4: Recover faster by consuming a complete protein within 30 minutes of uploading your race to Strava. By including recovery in your training routine, you can bounce back faster and get stronger making you ready for your next ride.

BCAAs — Invest in Muscle Insurance 

  • Rule of Thumb #5: Protect your muscles and stay sharp with 3,000 mg of amino acids per hour. Branched Chain Amino acids (or BCAAs) are the building blocks of proteins, and can start repairing your muscles while running. GU helps protect your muscles from damage by including BCAA’s in all GU energy products. BCAA’s are a GU HQ favorite because they help fight muscle soreness, and we believe any time is a good time for BCAA’s; pre-run, mid run and post run!

BONUS TIP: Six Reasons to Take BCAAs Today!



GU Essentials – The Foundation of a Good Plan


  • Energy Gels – 100 calories, delicious → Great for training.
  • ROCTANE Energy Gels – 100 calories, MORE amino acids, MORE sodium → Reach for these when it’s time to get serious.

What’s the difference? Click here to learn when to reach for a Roctane Energy Gel. 

  • ROCTANE Energy Drink Mix — 250 calories per serving, packed with amino acids → Keep it simple with all-in-one hydration and energy.
  • Energy Chews — 90 calories per serving, portable & delicious → Mix it up with the GU you can chew.
  • Energy Stroopwafels — 150 calories, a delicious & easily digestible solid → perfect for pre-race or along the way.








  • ROCTANE Electrolyte Capsules — Salt for sweaters, ginger for the stomach → Two caps’ per hour to get the electrolytes you need!
  • Hydration Drink Tabs — delicious, good for traveling, low-calorie → the best way to amp up plain water with electrolytes.


  • ROCTANE BCAA Capsules — 1500 mg of amino acids, super portable → Anytime is a good time to protect your muscles.
  • ROCTANE Protein Recovery Drink Mix — replenish with the perfect mixture of carbs, protein, electrolytes, and amino acids → always refuel within 30-60 minutes of finishing a big effort.


Tips from the PROs

Want more? Here are some tips to help you optimize your nutrition, training, and racing:




Nothing is worse than seeing spent packets on the sides of roads and trails. We know that our packets have an impact, so we’ve partnered with TerraCycle create a free recycling program for performance nutrition packaging. It’s simple: just sign up for TerraCycle for free, collect your sports nutrition wrappers (we accept any brand!), print out a free shipping label, and send a box or container with your empty sports nutrition packets. TerraCycle will convert these hard-to-recycle products into garden tools, park benches, and more. Join us here in saying #NotTodayLandfill!

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