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Training for a Marathon? Tips to Keep You Going

Contributors: Christopher R. Mohr, PhD, RD and Sarah Klemm, RDN, CD, LDN

Published: February 24, 2022

Reviewed: February 18, 2022

Training for a Marathon? Tips to Keep You Going
Wavebreakmedia Ltd/Wavebreak Media/Thinkstock

It's race day. Marathon day 26.2 miles. You've been training for months and preparing for everything within your control. One of the biggest factors that will determine how you finish is sports nutrition and how you fuel your body. This can be the difference between barely finishing a race and finishing strong.

So what should marathoners eat? What should they drink? First, it's important to emphasize that nutrition for marathon training isn't limited to just a few days here and there, but critical throughout training and the days leading up to the race — in addition to what you eat and drink before, during and after the marathon.

Carbohydrates and Protein Are Important

As a general rule of thumb, the diet for someone who is training for a marathon should be carbohydrate-based to provide adequate glycogen to the muscles for energy during training and the event itself. On the flip side, protein often can be an issue since the focus is normally so heavy on carbs. While carbohydrates are important, it's just as important to get enough protein. Carbohydrates provide necessary energy. Protein provides the tools — amino acids — to build and repair damaged muscle from the miles and miles of training done each and every week.

Keep Hydrated

Hydration can be argued to be more important than carbohydrates, protein or fat. Dehydration is the single largest contributor to fatigue when training or racing. Sweating helps regulate the temperature of your body. This is important. However, the loss of fluids and electrolytes — primarily sodium — also means these need to be replaced to prevent becoming dehydrated and, subsequently, hurting performance. Here's how to stay hydrated before, during and after the race.

  • In the days before race day, it's important to drink plenty of fluids so runners arrive at the race in a hydrated state. Runners should drink fluids until their urine is a light straw color.
  • On race day, runners should already be hydrated and only need to "top off their tank." A sports beverage containing electrolytes and carbohydrates in addition to fluid can be helpful. Runners should stop drinking approximately 30 minutes before the race begins in order to give them time to use the restroom.

One reason hydration is important is because it takes just a 2% weight loss to hurt performance. For the average 164-pound woman, that's just over 3 pounds; something that can occur when exercising in the heat or humidity. Be sure to include hydration in your training plan and figure out which powders or sports beverages you prefer (and make sure to bring them with you on race day).

Replenish During the Race

Outside of hydrating during the race, it's important to consider your fuels to replenish your hard-working muscles. If you are running between an hour and two and a half hours, you likely will be fine with a sports beverage. Some runners like to take a carbohydrate gel, or "sport beans," at the half and 20-mile points, and water as needed.

However, if you are running a three- to five-hour marathon you may need more fuel. Consider your carbs (carbohydrate gel, sport beans) earlier, such as at the 10K mark and every 10K thereafter.

Recover with the Right Fuel After the Race

Celebrate with the right recovery fuels. It's not uncommon for runners to finish a marathon dehydrated. After crossing the finish line, grab a bottle of water or sports drink as soon as possible. In the hours following a marathon, runners should continue to hydrate and drink 24 ounces of fluid for each pound lost during the race. Be careful not to over hydrate with water alone; runners will want to focus on replacing vital electrolytes that they lost while running. This comes most easily from a sports drink.

It's also important to consider protein to help your muscles recover. Make sure to eat a solid meal, including some lean protein with foods that are lower in fiber and fat. Because it's common for runners not to be hungry post exercise, low-fat chocolate milk or a sports drink with whey protein may be easier to consume.

One other important note — while there are many tips, tools and suggestions throughout this article, it's important to remember to never try anything new on race day. Always do the experimenting during a training run, so you know how your body will handle whatever fuel you are using and can best be prepared to finish the race strong.

For personalized nutrition guidance, consult a registered dietitian nutritionist who specializes in sports nutrition.

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