We all need energy in order to exercise and work out. Whether your goal is to lose weight, gain muscle, or train for a sport, everyone needs a certain amount of energy (Earle & Baechle, 2004). Carbohydrates represent the main energy source for our body. In addition, carbohydrates are necessary for complete metabolism of fatty acids, which helps prevent ketosis (a potential harmful condition). So when you see people cutting out carbs completely from their diet, they are not only depriving their body of energy to exercise (hence they are cranky), but they are also putting their body at risk for ketosis.
The body stores carbohydrates in the form of glycogen within the liver and muscles. The muscle glycogen storage represents the largest reserve, followed by liver storage, and a small percentage in the blood (McArdle, Katch & Katch, 2010).
Role of Carbs
- Energy source: Main energy source for exercise
- Protein sparer: Helps preserve our body’s protein tissue by not breaking it down for energy; a lack of glycogen stores causes the body to derive glucose from our amino acids (protein), which is not what we want
- Prevents ketosis: parts of carbohydrate breakdown assist in fat oxidation, which ultimately helps prevent accumulation of ketone bodies (ketosis)
- CNS fuel: our central nervous system needs a continuous stream of carbohydrate energy for proper functioning; it solely relies on carbohydrates for energy; a lack of this energy to the CNS can impair exercise performance and if sustained, can ultimately lead to unconsciousness and brain damage
The recommended intake for physically active individuals, according to exercise physiologists, should be around 60% of daily calories. For high intensity training, it is recommended to increase that percentage to about 70% of total calories (McArdle, Katch & Katch, 2010).
Scientific evidence has proven that a carbohydrate deficient diet depletes muscle and liver glycogen at a rapid pace. In addition, it impairs performance in short anaerobic exercise and prolonged intense aerobic exercise (McArdle, Katch & Katch, 2010).
What to eat?
- Whole Grains (pasta, cereal, bread)
- Vegetables (broccoli, asparagus, etc)
- Fruits (oranges, berries, pears, etc)
Moral of this blog: Eat your carbs!
McArdle, W. D., Katch , F. I., & Katch, V. L. (2010).Exercise physiology. (7th ed.). Baltimore, MD: Lippincott Williams & Wilkings.
Earle, R. W., & Baechle, T. R. (2004). Nsca's essentials of personal training. Champaign, IL: Human Kinetics.