Carbohydrates as a primary source of energy
As we have discussed in the previous article, nutrition plays a vital role in exercise. Today we will discuss one of the primary macronutrients that is a source of energy for most activities, especially when running a marathon. Furthermore, I will give examples of breakfast for Race Day and food after the race.
What are carbohydrates?
Carbohydrates are molecules composed of carbon (carbo), hydrogen, and water (hydrate). These are divided into monosaccharides, disaccharides, polysaccharides, and fiber.
The monosaccharides are the most basic component of carbohydrates, within which we have glucose (sugar in grapes), dextrose (sugar in fruits), and galactose. We find these in our daily diet, with glucose being the main used and galactose the least.
The disaccharides are made of two monosaccharides, with the most important being lactose (which comes from milk), sucrose (table sugar, sugar cane, beetroot), and maltose (malt sugar).
Polysaccharides are the more prominent compounds. Within them, we find starches, glycogen, and fiber, the primary forms of storage of carbohydrates in our bodies.
Muscle glycogen is the primary source of fast energy and is easy to obtain for the working muscle. The rate at which this oxidates largely depends on the intensity of the exercise. However, the hepatic glycogen's primary function is to stabilize the blood glucose levels, which is the brain fuel.
Carbohydrates consumption for athletes
In general, athletes train daily, which means it is crucial to replenish muscle glycogen. It is recommended that the amount of carbohydrates we should be consuming should be calculated from the body weight and the amount of training. Depending on the exercise intensity, the recommendations are as follows:
- Moderate training intensity (1 hour of training per day) 5-7g/kg of body weight daily.
- Moderate to high training intensity (1 to 3 hours of training per day) 7-12g/kg of body weight per day
- Very high training intensity (more than 4 hours of training per day) 10-12g/kg of body weight per day
It is worth mentioning that the food's glycemic index will influence how fast or slow these are absorbed. Foods with a high glycemic index include white bread, boiled or oven-cooked potatoes, cooked white rice, gummies, watermelon, and pastry. Foods with a moderate glycemic index include bagels, donuts, 250ml of beer, toasted white bread, ice cream, energy bars, and honey. Foods with a low glycemic index include potato chips, cookies, chocolates, 250ml of orange juice, muesli, apples, whole milk, tomatoes, lentils, spinach, broccoli, and asparagus.
The combination of these types of carbohydrates consumed during exercise or a race will also influence a greater acceptance and absorption of these to enable you to continue with energy and reach your goal.
Breakfast for Race Day
Regarding the ingestion of carbohydrates before exercising, the recommendation is to do so between 3 to 5 hours before starting to ensure glycogen is replenished in the liver after the nightly fasting. This should ideally be a food rich in carbohydrates (140g to 300g), for example, if you are planning to run a marathon, it's important to know how to fuel your body properly with carbohydrates. A breakfast rich in carbohydrates can help you start the race with the necessary glycogen stored in your muscles and liver, while a post-race meal with carbohydrates and protein can aid in glycogen replenishment and muscle recovery. By following the guidelines for carbohydrate intake based on training intensity and body weight, and choosing foods with the right glycemic index, you can maximize your performance and recovery. So, be sure to plan your meals accordingly and stay hydrated throughout the day.
