The best carbs for athletes

Which carbs are bad for you? Which are bad carbs for athletes?

Literally, try googling this. You’ll get answers. It’s weird.

Carbs, or carbohydrates, are an important part of everyone’s diet. They are even more important for athletes and for growing adolescents. No carb is the “bad one”. Read on for info on the best carbs for athletes.

Good carbs for athletes. To pin this image, click here!

What is a carb anyway?

Carbohydrates are part of the food we eat. They make up one of three macronutrient groups (the other two being protein and fat). 

The science-y stuff

Carbs are made up of carbon, hydrogen and oxygen in a very specific ratio of C:O:H2. There are a couple ways of classifying carbs that people use when talking about foods. In terms of chemistry, there are four types: monosaccharides, disaccharides, oligosaccharides, and polysaccharides.


The monosaccharides have only one carbon, and are rarely found by themselves. The three main monosaccharides you have possibly heard of are glucose, galactose, and fructose. Glucose is what people mean when they talk about blood sugar. Galactose comes from milk sugars. And fructose is the sweetest of all.


Disaccharides are made up of two monosaccharides. There are a lot of them, but the three that are most important in human nutrition are sucrose, lactose, and maltose. Sucrose is table sugar. It is made of fructose and glucose, and is found naturally in many items like fruits and grains. Lactose is milk sugar, and is made of glucose and galactose. Maltose (two glucose molecules) is not really found naturally in food items. Our bodies make it as we digest carbohydrates. It is also used in commercial food products.

carbohydrates are one of three micronutrients, along with protein and fat


Oligosaccharides are made up of a few monosaccharides (3-10). Some oligosaccharides are dietary fiber. I’m still not super sure why these get their own classification, separate from polysaccharides. But I double checked, and they do, so here they are, with their own heading an everything.


Polysaccharides are the form in which we often eat carbohydrates. They are made up of many monosaccharides (more than 10). Some polysaccharides are dietary fiber. Some polysaccharides are starch. And we also store polysaccharides in our bodies, as glycogen. More on all of that later (in a section that hopefully won’t be skipped by science-hating people).

Types of Carbs in the Diet

When you hear or read something about carbohydrates, you will probably come across these terms. 

Simple carb

A simple carb is a very short chain of sugar molecules. These are rapidly digested and provide easy, quick energy for the body. You can find simple carbs in fruit, vegetables, sweets, processed grains, and dairy products.

Added sugars

As the name suggests, added sugars are those which are added to a food item rather than occurring naturally in that item. A good example to help explain the difference is canned fruit. Fruit contains a lot of natural sugar. Fruit canned in water or fruit juice has no added sugars. However, fruit canned in a sugary syrup has natural sugars from the fruit and added sugar in the syrup.

There has been a lot of press in the past few years about added sugars. Public health guidelines have limits on how much added sugar people should eat. The food nutrition label was changed to include this information, which can sometimes be confusing.

A good example to help explain the difference is canned fruit.Fruit contains a lot of natural sugar. Fruit canned in water or fruit juice has no added sugars. However, fruit canned in a sugary syrup has natural sugars from the fruit and added sugar in the syrup.

A label for maple syrup, which is entirely sugar, shows no added sugars. But a processed muffin with maple syrup as the sweetener will have all the sugar from the maple syrup included on the added sugars line.

can of peaches
If your canned fruit is is syrup, it has added sugars.

(If you’re curious, my general guidance about added sugars is the same as my advice about most things: use your common sense and don’t stress.)

Complex carb

A complex carbohydrate is one with a longer chain of sugar molecules. You can find complex carbs in whole grains, vegetables, and fruit. One special polysaccharide, glycogen, is how we store energy in our muscles to use later. Other complex carbs are fiber and starch.


Fiber is an undigestible complex carb from plants. This means that our bodies cannot break it down, and it passes through our system relatively intact. Fiber comes in two types: soluble (viscous) fiber dissolves in water, and insoluble (non-viscous) fiber does not. You may also come across the terms “fermentable” or “non-fermentable” to describe these differences.


Starch is a digestible complex carb. This means our bodies can break it down and use the sugars for energy. Sometimes you’ll hear the word “starchy” when referring to a vegetable: this simply means that the vegetable contains starches.

Resistant starch

This is starch that doesn’t break down completely in the digestive process, so some of it is still intact when it gets to your large intestine. Some people get upset bellies when they eat a lot of resistant starch (think underripe bananas). Some resistant starches have health benefits; for example, some are prebiotics – see the next section.


Prebiotics are fibers or resistant starches that feed the good bacteria in our large intestine. These bacteria then produce substances that are beneficial to the body.

Carb is not a bad word

Despite what you may have heard from diet books and the internet, carbohydrates are not evil terrible things that will make you sick and shorten your life. Carbohydrates are in fact one of three macronutrients that our bodies need for optimum health and performance. They are responsible for many important functions in the body. Plus they taste good. Read on.


Carbohydrates are the main source of energy for the body. All macronutrients can be turned into energy, but carbohydrates are by far the most efficient. This means that every one of our cells uses carbs to keep going, and also means that we can have energy to go through our days.

Extra carbohydrates are stored in our muscles as glycogen. Most people can store up to 18 hours of energy in their muscles this way. If you are burning energy and run out of carbs from food you’ve eaten recently, your body can break down the glycogen in your muscles and use that. (Replacing muscle glycogen is one reason it’s important to eat right after vigorous exercise.)

Happy gut bacteria are good for you!


Remember, fiber is an undigestible carbohydrate. Soluble fiber can slow down foods in our digestive tract, which allows more nutrients to be absorbed. Insoluble fiber can bulk up our bowel movements, decreasing constipation.

Prebiotics fibers feed good bacteria in the digestive system. These good bacteria produce substances that can serve as energy for the cells lining our large intestine, can help regulate the movement of food through our digestive tract, and support blood flow. 

Heart health

Soluble fiber can bind to fats in the blood, and decrease cholesterol levels which decreases risk of heart diseases. Some substances created by prebiotics can help regulate cholesterol as well.

Brain health

Our brains prefer to use glucose as an energy source, so carbs are more important for this than any other type of macronutrient. 

In addition, some substances created by prebiotics have positive effects on brain function. Not to get too into the weeds here, but different prebiotic strains have been shown to influence memory, learning, mood and emotions.

Cancer prevention

I’m going to be real here: there is no proven way to prevent cancer. However, some things have been shown to be associated with (not necessarily cause) lower cancer risk. One of those things is consumption of prebiotics. 


Carbohydrates taste good. This alone can be a reason to eat them. You’re allowed to eat foods just because they’re yummy, or to add sweetener to other foods to make them taste better. (There are important biological reasons why carbohydrates taste good to us; if you care, let me know, and I’ll write about it.)

So what are the best carbs for athletes?

Simple Carbohydrates

Simple carbohydrates are great right before or after a game, practice, or workout. They can provide easy energy beforehand, and afterwards are the best way to quickly replenish glycogen stores and blood sugar.

Simple carbs also provide sweetening to foods, like adding syrup to pancakes or brown sugar to oatmeal.

Most foods are a mix of simple and complex carbs. Some great plant-based foods that are mostly simple carbs for athletes to eat right before exercise are:

  • dried fruit
  • fruit
  • rice milk, some nut milks, coconut milk drinks
  • fruit juice
  • sports drinks
  • applesauce
  • smoothie made with fruit, fruit juice, or milk

Complex Carbohydrates

Complex carbohydrates are great for fueling before games, practices or workouts. They are also important for our everyday diets, so don’t just eat complex carbs around exercise times. 

Again, most foods are a mix of complex and simple carbs. Some great plant-based foods that are mostly complex carbs for athletes are:

potatoes and sweet potatoes

grains – white and brown rice, oatmeal, polenta, quinoa, buckwheat, barley, popcorn

grain products – pretzels, crackers, pasta, bread, bagels, cereal, granola bar, cereal bar, pancakes and waffles

Bottom Line

Did you skip to this section? Here’s your very brief summary:

Eat both simple and complex carbohydrates for quick energy, long-lasting energy, and a variety of health benefits. 

About the Author

Sarah Skovran, RDN LD ACE-PT, is a Registered Dietitian Nutritionist, ACE certified personal trainer, mom of a teen athlete, and is mostly vegan. She writes about sports nutrition, plant based eating, and adolescent nutrition at Plant Powered Teens, and sees in-person clients at her private practice in Maine.


Cerdó T, Ruíz A, Suárez A, Campoy C. (2017). Probiotic, prebiotic, and brain development. Nutrients. 9(11), 1247. DOI: https://10.3390/nu9111247

Hoyles L, Snelling T, Umlai U-K, Nicholson JK, Carding SR, Glen RC, McArthur S. (2018). Microbiome-host systems interactions: protective effects of propionate upon the blood-brain barrier. Microbiome. 6(55). DOI:

Rowland I, Gibson G, Heinken A, Scott K, Swann J, Thiele I, Tuogy K. (2018). Gut microbiota functions: metabolism of nutrients and other food components. European Journal of Nutrition. 57, 1–24 . DOI:

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