How Many Carbs Should You Eat Before A Workout?

The impact of per-exercise carbohydrate intake on athletic performance has long been a hot topic of interest within the world of sports nutrition.

Consuming the correct amount of carbohydrates before moderate to intense activity is an important performance consideration for most people, especially in light of the fact that carbohydrate depletion has been shown to decrease athletic performance.

In today’s article my superstar writing intern Kat delves into the science behind how pre-training carbohydrate intake impacts performance and delivers specific recommendations to help you better understand the types and amounts of carbohydrates you should consume to optimize your physical output in the gym or on the field (or wherever else!).

Take it away Kat!

Carbohydrates Before Training

Written & Researched By Kathryn Durston and Reviewed/Edited By Yours Truly

Carbohydrates are an integral component to pre-workout nutrition due to their impact on performance and a person’s ability to manipulate and adapt to daily training demands.

The Academy of Nutrition and Dietetics captures this sentiment well in the quote below:

“There is significant evidence that the performance of prolonged sustained or intermittent high-intensity exercise is enhanced by strategies that maintain high carbohydrate availability, whereas depletion of these stores is associated with fatigue in the form of reduced work rates, impaired skill and concentration, and increased perception of effort.” 

Ingesting carbohydrates provides the body and brain with glucose, which is our primary source of fuel while working out and at rest.

Our muscles also have the capacity to store glucose for use as energy in the form of glycogen.

A 2018 paper from the Nutrition Reviews journal summarizes it aptly:

The ability of athletes to train day after day depends in large part on adequate restoration of muscle glycogen stores, a process that requires the consumption of sufficient dietary carbohydrates and ample time.

The keywords here being sufficient dietary carbohydrate and ample time, two of the considerations which I will explore in this post.

Let’s get to the good stuff.

How Many Carbs Should You Consume Pre-Training?

The general recommendations from the Academy, DC, and ACSM is to consume one to four grams of carbohydrates per kilogram of body weight in the hours before any prolonged exercise ( >60 minutes in duration).

This is the “magic number” so to speak when it comes to enhancing performance.

Let’s break this down further.

Pre-workout carbohydrate range: (Bodyweight (kg) x 1 g) to (Bodyweight (kg) x 4 g)

So if you weigh around 70 kg, you should be consuming 70-280 grams of carbohydrates before your workout.

For my American friends, to get from pounds to kilograms just divide by 2.2! 

Higher level athletes with intense and lengthy training regimens may benefit from carbohydrate consumption on the higher end of this spectrum, whereas many of us “average” folk who just like to put in the work will very likely thrive on the lower end.

Two examples to help you visualize what this looks like:

An example of a meal with around 70 grams of carbs would be a cup of cooked oatmeal with a banana and some maple syrup.

Another example of 70 grams of carbohydrate might be 1 cup of cooked spaghetti with 1/2 cup cooked lentils and some tomato sauce.

Of course there are a wide range of meals to choose from depending on your needs and preferences and you could amplify the amount of these components to get higher amounts of carbohydrates in a given meal.

How Long Before Your Workout Should You Eat?

Timing is important.

No one wants to be jumping or sprinting 15 minutes after a huge meal nor do they want to go into an intense workout completely depleted, which is why a time frame of one to four hours prior to activity is generally recommended.

You must strike the right balance between the precise timing and amount of carbohydrates that works best for you within these ranges – personal experience should play a big role in driving these choices.

This 2014 study out of the Sports and Performance issue saw a consistent improvement in athletic performance when a carbohydrate-rich, pre-workout meal was eaten in the optimal range of two to three hours before their workout.

Carbohydrates consumed less than 60 minutes before a workout had a considerably less improvement on exercise performance.

So now that we know how much and when – how do we decide which types of carbs you should consume?

Let’s find out.

Best Sources of Pre-Workout Carbs?

While it’s pretty clear that not all carbohydrates are created equal, we still have to ask how much the types of carbohydrates one consumes matters as it relates to pre-workout performance.

It’s possible that some people may benefit from avoiding consuming large amounts of fat, protein or fibre as part of their pre-workout meal as these components slow down the transit of food and could increase the risk of gastrointestinal issues during an event.

And so while very high fibre nutrient dense foods such as legumes and veggies are generally amazing choices, you may not want to consume them in massive quantities directly prior to training or a workout.

A paper published in the International Journal Of Sport Nutrition And Exercise Metabolism  really puts the totality of this discussion together.

The study found that athletes who ate within 30 minutes of a triathalon, or who consumed a meal greater in fat and protein content,  were more likely to experience GI symptoms such as bloating and vomiting.

Final Thoughts And Next Steps

The goal of today’s article was to demonstrate that pre-training nutrition is a carb-dependendent endeavour that must be individualized and adapted in order to achieve the greatest performance benefit.

I hope that today’s article gave you some valuable insights in this regard and that the next time you have an intense training session or workout on the agenda that you know which and how many carbs to reach for as well when to reach for them.

Don’t forget that working with a registered dietitian like Andy, who you can contact here via his website, is an amazing way to optimize your nutrition planning for any sports or physical activity routine.

Kathryn Durston

PS: Don’t forget to read Kat’s EPIC article on collagen.

And if you’re looking for more sports nutrition information content – you will find it below.

How Much Protein Do You REALLY Need?

My Interview With An Olympian (ABOUT FOOD!)