Nutrition plays a huge role in proper training and the ability to perform your best for a half marathon. It is important to incorporate the appropriate nutrition during the weeks of training and not just the week of race day.

I might just make your day when I tell you that CARBS (you know that macronutrient that everyone keeps saying they need to stop eating to lose weight) will be your best friend for training. Yep, that is right…you NEED carbs and lots of them to help you get to your peak performance.

CARBS…Load Me Up Or Let Me GO

Carbohydrates are the body’s first energy source. Carbohydrates are necessary to fuel your muscles so that you can actually enjoy your training without feeling tired and weak. We store carbohydrates in our liver, muscles, and blood but most of it is stored in our muscles. The carbohydrates in the muscles are used for exercise whereas the carbohydrates in the liver are released into the bloodstream to regulate your blood sugars and feed your brain (which is also important in exercise).

Preparing for an endurance event like a half-marathon/full-marathon (or anything that lasts over 90 minutes) requires CARB LOADING. So many people misunderstand what carb loading really means and end up over indulging in the wrong kind of carbohydrates or the wrong amounts of carbohydrates and actually hurt their performance instead of helping it.

Let’s take a look at how to eat right when training…

1. Carb Loading Daily, Not Just The Night Before

Your daily intake should consist of OVER 50% of your daily calories from carbohydrates with a balance of adequate protein and healthy fats. Nancy Clark, the sports dietitian that knows her stuff and has written a whole book on it says, “a daily carbohydrate intake of about 3 to 5 grams of carbohydrate per pound of body weight prevents chronic glycogen depletion and allows you to not only train at your best but also compete at your best.” Don’t sell yourself short when it comes to carbs. Your muscles will always feel fatigued if you constantly follow a low carb diet, so treat your muscles right and eat your carbs!

2. Eat Your Daily Carbohydrates Even On The Days You Don't Train

It is important to get enough carbohydrates on the days you aren't training hard. Your muscles need these days to rest and build up more glycogen stores that have been depleted from your hard work on your training days. You know those days after a workout, when you feel like you want to raid the fridge and eat everything because you are so hungry? That is most likely because your muscles NEED it to replete what you have used up. So eat up!

3. Choose The Right Carbs

I know I got you all excited thinking you could eat a plethora of carbohydrates and get your fill of all the refined breads and sweet treats because you are going to run it off…BUT the kind of carbs you eat matters too. Try choosing complex carbohydrates and foods that are rich in fiber (unless it is the night before the race, and I would probably stay away from anything too fibrous so you can avoid having major intestinal issues the day of the race). Some good choices for complex carbs would be: oatmeal, wheat bread, fruits, and vegetables. Try incorporating more of these into your daily intake.

4. More Doesn’t Always Mean Better

Carb loading the night before the race does not always mean you can eat whatever carbs you want and as much as you want. If you eat too much the night before a run, you might end up feeling weighed down and bloated, not to mention the intestinal distress you might put on your body (and let me just say, there will be port-o-potties available but there will also be lines…lots of lines that your bowels may not wait for).

5. Adequate Protein

Protein is important to build and repair muscle tissue, replace red blood cells, and produce hormones. In endurance exercise, such as a half marathon, only 5% of energy comes from protein in your diet. Nancy Clark's Sports Nutrition Guidebook talks about how "humans do not store excess protein as muscle, protein, or amino acids, so we need to consume adequate protein each day" {ADEQUATE...not more than required}. There are SLIGHTLY increased protein needs for athletes to repair muscle damage during training and support new muscle tissue building. Here is the recommended protein in grams per body weight in pounds:

  • Sedentary adult: 0.4g/body weight
  • Average male endurance athletes: 0.5-0.9g/body weight
  • Average female endurance athletes: 0.5-0.8g/body weight


But seriously, drink fluid. ALL DAY, EVERY DAY. Dehydration puts stress on the body, increases your heart rate, burns more glycogen, and makes exercise feel harder than it should. It is important to consume adequate fluids. Drinking fluids the night before the race helps to hydrate your muscles but gives you enough time to eliminate the excess prior to the race {you don't want to drink too muchthe morning of a run because there is nothing worse than a sloshing stomach}. Also good to note that drinking salted foods and fluids (like Gatorade) before a race can help to retain fluid and in return help you to run longer and better.

Don't forget to replace your sweat losses during training. One pound of body weight lost in sweat after a run should be replaced with about 16 ounces of fluid. So hop on the scale and drink up!

7. Make Sure To Eat Breakfast On Race Day

This does not have to be an All-Star Breakfast Special…I am just talking about a little something to start your day. Eating a little something the morning of the race can help to regulate your blood sugars and prevent you from being hungry. Make sure to choose foods that your body is familiar with, which we will talk about next.

8. Don’t Eat Something Different The Night Before Or Morning Of Race

Use the training weeks as trial runs for your intake. Learn what works for your body and what doesn’t so that you aren’t having surprise GI issues during the race. When Thomas and I went to New Orleans, we ate some pasta (heavy in sauce) for dinner. Thank goodness it was an early dinner because I was sooo sick from eating it that we had to go straight back to the hotel, get in bed, and lay in the fetal position. I don’t eat a lot of pastas on a normal basis, nor do I have a lot of oil and high fat sauces on the reg…so this was not the smartest decision I ever made. Luckily I still made it through the race, although it was not my best time.

9. Replenish Yourself With Energy Gel Along The Way If Needed

Energy gels like Gu or PowerGel are great for endurance events like a half marathon where you need a quick source of glucose to regulate your blood sugars and sustain your energy level. I usually use them for runs over 7 miles when training and for the actual race. They will actually be handing these out at the race and usually are given at mile markers 8,10, 11 (or somewhere in between) so take advantage of them. I would definitely recommend training with the energy gels before the race though to make sure how your body reacts to them. 

10. Go Enjoy Lots Of Well Deserved Food After The Race

You have worked so hard and have burned more calories than you probably ever have the day of the race. Grab yourself lots of food and fluids to refuel!!! Enjoy yourself and be proud of what you have accomplished.

There is so much more that I could share with you about proper nutrition for exercise that I could probably write a book about it. Good news is there is already one written for you called Nancy Clark's Sports Nutrition Guidebook that is awesome and worth the go check it out for more information!

Need more answers? Feel free to message me with any questions or concerns! I hope this helps you to properly fuel your body to perform to the best of your ability!