What Do Carbohydrates Do in the Body?

If you're a sporty person, you're probably already aware that carbohydrates are needed to prevent drops in performance and reduce the risk of injury. Today, we'll explain exactly what they do.
What Do Carbohydrates Do in the Body?

Last update: 30 October, 2020

Carbohydrates are one of the three macronutrients that the body needs, and they basically consist of sugars, starches, and fibers. They’re essentially an energy source, which is why they’re so important for athletes and people who practice sports. Today, we’ll look at exactly what carbohydrates do in the body.

However, carbohydrates are less important for people who follow a sedentary lifestyle. This doesn’t mean that they should avoid them, but they should certainly try to consume less in order to stay healthy and avoid health problems.

Carbohydrates provide energy

People who do anaerobic exercise are dependent on sugar. They need a regular supply of carbohydrates in order to maintain performance levels.

This is because of the way carbohydrates work in the body. In fact, according to a study published in the journal Nutrients, a regular and consistent supply of sugars is linked to better recovery after exercise.

Making sure that you get enough carbohydrates immediately after high-intensity exercise improves the replenishment of glycogen reserves and also reduces the risk of muscle breakage in later activities. Also, consuming carbohydrates along with proteins maximizes the replenishment of glycogen.

However, although carbohydrates are the main energy source for most athletes, there are other sports that don’t require carbohydrates.

A collection of foods rich in carbohydrates.

One such example is strength training, which has been scientifically proven to be perfectly safe when sticking to a ketogenic diet. For people doing strength training, a lack of sugars is no big deal for their performance levels.

Secondary functions of carbohydrates

Whilst the main function of carbohydrates is to provide energy, they also play a role in other bodily functions. For example, they also help in the construction of cell membranes and provide cells with rigidity.

But, the good news is that you don’t need to consume carbs for these bodily functions. The body is able to produce glucose in the liver from proteins and fats.

This process is called gluconeogenesis. This process means that you don’t need to consume sugars to meet your body’s carbohydrate needs.

As a result of this, current recommendations are that we should try to significantly reduce our carbohydrate intake, except in the case of athletes and sporty people. For people with a sedentary lifestyle, eating too many carbohydrates could lead to a number of health problems.

Current studies have even looked at whether reducing sugar intake can slow tumor growth in cancer patients. The most recent results are really quite fascinating. However, this doesn’t mean that you should avoid carbs completely. You just need to be aware of how many you’re really consuming.

A man and woman running through the park.

Not all carbohydrates are the same

Despite performing the same function, there are different types of carbohydrates depending on how easily they’re absorbed into the bloodstream. There are two groups: high glycemic index and low glycemic index. The first group consists of simple sugars, which are the most harmful for the body.

Low glycemic index carbs are complex sugars and are much more beneficial for the body. One of them is fiber, which plays an important role in intestinal transit.

Carbs are a source of energy

So, in summary, the main job of carbohydrates is to provide the body with energy. As a result, people who aren’t very active should ideally reduce their carb intake, or start exercising more often!

However, athletes and people who regularly practice sports need a regular and consistent supply of sugars in order to maintain performance levels and reduce the risk of injury, particularly those who practice anaerobic exercise. And when choosing a source of carbohydrates, the preference should always be for low glycemic index carbs since they’re the healthiest.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.


  • Alghannam AF., Gonzalez JT., Betts JA., Restoration of muscle glycogen and functional capacity: role of post exercise carbohydrate and protein co ingestion. Nutrients, 2018.
  • Shaw DM., Merien F., Braakhuis A., Maunder ED., Dulson DK., Effecto of a ketogenic diet on submaximal exercise capacity and efficiency in runners. Med Sci Sports Exerc, 2019. 51 (10): 2135-2146.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.