Carb loading for runners is very well known and established in the literature and can have a 2-3% improvement on performance! But what does that look like with diet? Let’s break down some of the best foods for carb loading!
Maybe you’re familiar with the idea of carb loading for running, but you don’t know where to begin or how to include so many carbohydrates in your diet.
What are the best carb loading foods for running anyway?
Have no fear – as sports dietitians, this is what we do!
We love working with you on your individual dietary patterns and preferences to help you eat enough food, especially in the days leading up to your race.
We should first start off by reminding you of the importance of carbohydrates, since we know that low carb running, while popular for it’s own reasons, won’t improve performance or PR’s.
Carbohydrates are the primary fuel source for the brain and the body. They are the primary fuel source for endurance exercise. In this article, we’re going to discuss a fueling strategy often implemented by endurance athletes – carb loading.
What is Carb Loading?
Carb loading involves an increased intake of carbohydrate-based foods while simultaneously decreasing exercise so that the carbs are being stored rather than used for energy. This is usually referred to as a “taper” period before a long run or race.
Research has shown us that the human body can store approximately 90 minutes’ worth of carbohydrates to be used as fuel for endurance exercise.
Therefore, if you have a race coming up that is going to be longer than 90 minutes, carb loading may be beneficial for your performance and endurance.
The increase in carbohydrate intake helps to delay the onset of fatigue, and the odds of hitting the wall, during the race.
There are different methods for carb loading including duration of the loading period as well as the amount of carbs to intake.
Throughout this article, we’ll discuss the best carb loading foods for running.
Here are two of the most common ways to carb load.
- Longer taper, less carbs – Taper 3-4 days prior to the race while increasing carbs to 8-12g/kg of body weight. For example, a 150 pound athlete would increase their carb intake to 545 – 818g of carbs per day (approx. 27-41 “servings” of carbs per day).
- Shorter taper, more carbs – Taper 1-2 days prior to the race while increasing carbs to 10-12g/kg of body weight. For example, a 150 pound athlete would increase their carb intake to 682 – 818g of carbs per day (approx. 34-41 “servings” of carbs per day).
As you might imagine, it may be quite difficult for someone to hit the above goals of 27-41 servings of carbs per day.
That is a lot of food, which is why we want to be strategic in choosing the best carb loading foods. Many of these high carb lunch ideas are great too.
The Best Foods for Carb Loading
The amount of carbohydrates ingested is more important than the type of carbohydrate or the foods consumed. If an adequate amount is taken in, the foods don’t really matter as much.
That being said, for most people, it is going to be easier and easier on the GI system to intake more simple carbohydrates or low-fiber carbohydrate foods and beverages.
It will also be easier to “fit” these carbs in more easily.
Some good foods to increase or add in while carb loading include:
- Pasta (2 oz = 42g)
- Bread (1 slice = 15g)
- Potatoes (1 medium = 37g)
- Rice (1 cup = 45g)
- Fruit (1 medium banana = 27g)
- Pretzels (1 oz. = 23g)
- Crackers (5 crackers = 10g)
- Beverages containing carbs such as sports drinks (12 oz. = 22g) or 100% fruit juice (8 oz. = 37g)
- Honey (1 Tbsp. = 17g) or other sweeteners
- Baked goods such as muffins (1 medium = 61g) and cookies
- Candy such as fruit snacks (1 pouch = 19g)
*The carb amount per each food is the amount per serving size indicated and may vary by brand or type.
Including more simple carbs, or easy-to-digest foods, is going to make it easier for you to increase your carb intake while not feeling overly full.
If you take in a lot of high-fiber carbohydrate foods, you will likely feel more full and may have some GI issues leading up to the race.
The Best Way to Carb Load
Some of the best carb loading meals include simple carbs with liquids and starchy foods. Avoid the high fiber foods that will fill you up prematurely when you’re carb loading.
Seeing as the above calculations are quite hard for most people to hit, I like to take the practical tips approach with a lot of my clients.
I commonly say that this is an example of “nutrition is a science but it’s also an art”.
The science gives us these numbers but the art is figuring out how the science looks in real life. And how it looks for each individual person.
My practical tips for carb loading include increasing carbs at each meal, adding more carb foods to snacks, including liquid carbs, like juices, smoothies and sports drinks, and including salty foods to help with hydration.
For instance, if you typically have one slice of bread as part of your breakfast, consider upping that to two slices during your carb load.
If you typically have one serving of potatoes or rice at lunch, consider upping that to two, and so forth.
For snacks, if you typically snack on nuts in the afternoon, consider adding a piece of fruit or switching out the nuts for some pretzels and peanut butter.
Since we are increasing carbs, we will in turn, be reducing the amount of protein and fats during this time, which are more filling and will displace the carbs.
The goal is not to gorge on a buffet of carbs for the entire 1-4 days for which you are carb loading. Rather, increasing your carb intake slightly from your current intake will provide your body and muscles with the fuel they need.
You can refer to the performance plates for runners for ideas on how to restructure your plate.
Liquid carbs, such as fruit juices, smoothies, milks and sports drinks, are often easier and less filling than solids, so can be great additions to meals or additions throughout the day.
And increasing salty foods such as pretzels, goldfish crackers, soups, and jerky will help the body hold on to water, which is good for hydration.
The bottom line for carb loading foods is that the act of carb loading will likely only be beneficial for runs or races longer than 90 minutes.
Carb loading may also be more appealing for the competitive runner or athlete rather than the recreational runner or athlete, as carb loading has been found to maybe improve performance by 2–3%. Although that 2-3% improvement can translate to large numbers.
In general, 45-65% of total energy intake (calories) should be coming from carbohydrates.
During a carb loading phase, that may increase to 65-75%. Fun fact: It’s been found that Kenyan runners get greater than 75% of their energy from carbohydrates.
One study even found that physical inactivity plus a high carb (10g/kg of body weight) intake increased muscle glycogen stores by 90% after only one day.
So, this carb loading period does not have to be for a long time if you find it physically uncomfortable, or you don’t have several days to play around with the above-mentioned protocols.
To reiterate: The goal is NOT to feel uncomfortably full or miserable during the carb loading period.
Be aware that carbs help retain water so, during this time of increased carbs and decreased activity, it is common to see the scale go up from water weight. Rest assured that is normal and will be used for energy during your race.
Bussau, V.A., T.J. Fairchild, A. Rao, et al. Carbohydrate loading in human muscle: an improved 1 day protocol. Eur. J. Appl. Physiol. 87:290-295, 2002.
Jeukendrup, A.E.; Jentjens, R.L.P.G.; Moseley, L. Nutritional Considerations in Triathlon. Sports Med. 2005, 35, 163–181.
Onywera VO, Kiplamai FK, Boit MK, Pitsiladis YP. Food and macronutrient intake of elite kenyan distance runners. Int J Sport Nutr Exerc Metab. 2004 Dec;14(6):709-19. doi: 10.1123/ijsnem.14.6.709. PMID: 15657475.
Vitale K, Getzin A. Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations. Nutrients. 2019; 11(6):1289. https://doi.org/10.3390/nu11061289