The Effects of Carbohydrates on Your Workout

We’ve talked quite a bit about the effect of protein on your workout. We’ve discussed how protein affects your performance, protein and your metabolism, and how to enhance your training regimen with a protein supplement. But protein is only one of the three macronutrients. We still have to consider the role that carbohydrates and fats have to play. Look for our post on fats in the upcoming weeks. For this post, we’ll focus on the effects of carbohydrates.

First, we have to understand how your muscles use carbohydrates to understand the effects of carbohydrates on your workouts. In an article titled “How Does Your Body Use Carbohydrates?”, Rita Larsen, RDN explains that the body uses carbohydrates as a short term muscle fuel.

According to Larsen, “After carbohydrates are eaten, they are broken down into smaller units of sugar (glucose, fructose, and galactose) in the stomach and small intestine. Glucose is the form of carbohydrate that is transported by the bloodstream in the various tissues and organs, including the brain, where it is used as energy throughout the body.”

How Your Body Uses Carbohydrates

There’s something we need to understand about the effect of carbohydrates. The body stores carbohydrates if not used right away. According to Larsen, “The body will store glucose in the liver and muscles in a form called glycogen. This storage form is used by the body for energy when the body needs more glucose that is readily available in the bloodstream, for example after exercise.” The body cannot store unlimited amounts of glycogen. It can only store about 2000 calories at a time, making carbohydrates a short term, limited fuel for physical performance.

This is news for those carb loaders out there who eat a giant bowl of pasta before a race. Yes, the carbs are useful for energy, but keep in mind that you can only use and store so much. This is one of the effects of carbohydrates on your metabolism. If your body has glucose from carbohydrates available, it won’t burn protein as fuel. When we don’t consume enough carbohydrates and break down protein as fuel, it isn’t available for muscle development.

The Effects of Carbohydrates on Your Muscles

So, what are the effects of carbohydrates on our workouts? According to a document published by the Food and Agriculture Organization of the United Nations (FOA) titled “The Role of Carbohydrates in Exercise and Physical Performance”, a high carb diet was found to increase an athlete’s endurance:

“An early study exploring the link between diet and exercise capacity found that after a period on a high carbohydrate diet, endurance capacity on a cycle ergometer, doubled in comparison with the exercise times achieved after consuming a normal mixed diet. In contrast, a fat and protein diet reduced exercise capacity to almost half that achieved after normal mixed diets. This clearly showed the benefits of eating a high-carbohydrate diet before prolonged exercise and was the first to establish importance of the carbohydrate content in the diets of athletes preparing for competition.”

Different Exercises, Different Fuel

This study, however, focused on your energy needs if you are going for endurance, such as before a marathon. It’s different if you’re participating in a high-intensity strength training regimen, such as we practice here at Vertex Fitness.

According to the FOA, carbohydrate loading may not improve performance in sports which involve several brief sprints. “Sports which demand that their participants perform a combination of submaximal running and brief periods of sprinting, such as soccer, reduces muscle glycogen concentrations to critically low values.” This impairs performance, so carbohydrate loading probably does have some benefit in multiple-sprint sports.

There are no easy, clear-cut answers as to when and how you should take in carbohydrates. The answer depends on what type of activity you are doing . Your body needs a good balance of macronutrients to effectively fuel your workout.