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Fuel Your Run: Optimal Nutrition for Half-Marathoners

Written by Dr. Daniela Steyn

Are you preparing to run a half marathon like me? If so, you’re probably focused on training and building your endurance. But did you know that optimal nutrition and healthy lifestyle habits can have the biggest impact on your performance on race day? In this blog post, I'll share the strategies I use to stay energized, and at the top of my game before during and after race day.

I will run the Toronto Half-Marathon this Sunday. Here are the strategies I will implement this week leading up to race day. You can do the same!

You can easily improve your race day performance by optimizing your nutrition. Well-planned nutrition the week before and during your race prevents your body from 'hitting a wall' after 90 minutes when glycogen stores in your muscles and liver are depleted. You can tailor these half-marathon nutrition principles for shorter and longer distances.

It's not only race day nutrition that counts, but every day leading up to your race. Make sure you eat power-packed foods every day to nourish your body. You are what you eat. Your muscles need foods full of antioxidants, phytonutrients and protein. Eat different veggies from all the different colours of the rainbow. Make sure you have adequate protein at every meal. I will avoid high-fibre foods two days before the race to prevent tummy troubles on race day, so I will ensure I get a double amount of veggies in with every meal Monday to Thursday.

2. Hydrate well

Ensure you drink at least 2 litres of water daily this week.

3. Electrolytes

When you sweat, you lose electrolytes such as sodium, potassium, calcium and magnesium, essential for optimal muscle and nerve function. Ensure your electrolyte stores are full by replenishing them all week, not only on race day.

Eat foods rich in electrolytes. I like bananas, potatoes and nuts. Consider electrolyte replacement tablets/powders/sports drinks. Add some extra salt to your food this week.

4. Caffeine

Caffeine is a valuable supplement for runners to improve performance and increase alertness. It also reduces your perception of fatigue. Several studies show improved endurance performance. For my athletes who compete on a keto diet, caffeine might also be helpful to increase the use of fat as fuel.

Unfortunately, caffeine increases your heart rate, worsens fatigue and impairs performance; it can cause gut troubles, jitteriness and anxiety. So I slowly cut back and stop my caffeine intake the week before. Then on race day, I will have one cup of coffee (this is about 1mg/kg for me, safe ranges are up to 3-6mg/kg of body weight). You can try it as well. It will give you the boost you need without the side-effect of excessive caffeine.

Most of the athletes I work with don't sleep well the night before the race. I get it. We get way too excited. That's okay. One night of poor sleep won't break your race, do what you can to ensure good restorative sleep the rest of the week.

Before the race

Great pre-race food should be easy to digest and low in fibre (so you don't have to visit the porta-potty too frequently ;).

Try your race day nutrition before to know what works best for you. Foods I like and recommend to the athletes I work with:

  • Bananas are a great source of carbohydrates, potassium and vitamin C. They are easy to absorb and convenient to throw into your race-day backpack

  • Oatmeal is an excellent source of complex carbohydrates and fibre, providing sustained energy during your race. Adding fruit, such as berries or bananas, adds extra nutrition. You can add nuts for extra nutrition and healthy omega oils. If you easily run into tummy troubles, avoid the add on's, and stick with sugar.

  • Toast with nut butter: Toast with peanut butter / almond butter is a good source of carbohydrates, protein and healthy fats. This combination of fast and slow-release carbs ensures continued energy release while running.

During your race

Continue to drink fluids. If you drink water, you must replace your electrolytes to avoid hyponatremia. Energy drinks would typically have carbs and electrolytes.

If you follow a clean diet and would like to stick with whole foods, you can totally do it. Try your race nutrition out during long runs, as many of my athletes find their bodies having difficulty processing fruit sugars while running (read: stomach upset during your run).

Natural whole food options include raisins, dried mangoes, and Himalayan salt crystals in your race belt.

After your race

Getting protein, fluids, carbs and electrolytes within thirty minutes of finishing your race is essential for optimal muscle recovery.

For my peri and post-menopausal readers, avoid the post-run free beer and focus on nutrient-dense foods.

You can watch my YouTube video about race recovery here.

General running wisdom:

  • Define success for yourself. There will always be faster and stronger athletes.

  • Don't compare yourself to others. For this race, I will not even be comparing myself to myself. I know I won't run as fast as I did last year when I competed at the Triathlon World Championships and trained for three years to represent my country. I have different goals than a specific time or pace in this race. To me, success would be showing up and fitting a race into my hectic schedule. (Like many of you, I am a busy mom, doctor, business owner, and professor at our Medical University). Another goal is to finish strong and avoid injuries by letting my brain set the pace (rather than my heart, which feels like a racehorse and begs to be set free).

  • Most important, I am grateful for my amazing friends and running community. Your community is one of your pillars of health and wellness.

Check out my online triathlon nutrition course for women to learn more about taking your nutrition and running to the next level. You will get a 50% discount if you register now.

I have a free nutrition guide for female athletes HERE.

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