Are you confused on the best way to lose weight or to increase your athletic performance? The topic of carbohydrates usually falls at the center of this discussion. Low carbohydrate diets have been a popular trend for weight loss, as well as athletes seeking to improve performance. Diets focused on low carbohydrates, such as Atkins, South Beach and The Zone, recommend eating anywhere between 10% – 40% of calories from carbohydrates. Ornish and Pritikin diets recommend consuming at least 60% of calories from carbohydrates while limiting fat intake. With such conflicting opinions, what is the healthiest and most effective choice for you?
To choose the healthiest method understanding why carbohydrates are important to our health is key. Let’s start with the basics. Glucose (aka sugar), glycogen, and starch are at the foundation of carbohydrates. Glucose is how carbohydrates are moved in the body and is usually stored as glycogen or fat. Glycogen is the storage form of carbohydrates. It’s stored in skeletal muscle and the liver. Glycogen is important because it’s the primary source of energy during most forms of exercise, and plays a key role in physical and mental performance and fat loss. Starch is the plant storage form of carbohydrates. Starches are important because they can negatively affect blood sugar after a meal. This can cause increased fat storage among other unwanted health effects.
The intensity and length of an activity determine the body’s use of carbohydrates. Poor carbohydrate consumption results in the inability to restore glycogen. Therefore, if you are performing high intensity activities or are simply working long hours, energy and mental performance will be decreased because your glycogen stores are low. It also disrupts exercise adaptations contributing to overtraining, frequent injuries and frequent low energy levels.
So what are some general guidelines? A low carbohydrate diet in people doing weight lifting, sprinting, soccer, football, and basketball will decrease exercise performance. Individuals who perform these exercises do best on a diet that is 55-60% carbohydrates (6-10 g/kg/day). Ideally, 45% of carbohydrates consumed should be those less likely to affect blood sugar dramatically. For people completing marathons/triathlons or performing greater than 60 minutes of cardiovascular activity consuming more than half of their calories from carbohydrates (5-12 g/kg/day) is ideal. In most situations, carbohydrates more likely to increase blood sugar should be limited to 1-2 hours after exercise and only if other sources of carbohydrates are unavailable. All requirements are dependent on the intensity, amount, and length of training.
What’s the bottom line? Suitable carbohydrate consumption is critical for maintaining energy and for proper mental and physical performance and recovery. They are significant in helping to lessen conditions that can lead to overtraining and/or negatively affect health and well-being. Understanding how carbohydrates are used by your body will help you to choose the best and healthiest method for losing those few extra pounds or increasing your athletic performance. This important nutrient can be manipulated along with fats and proteins to optimize performance and to positively change body composition. Remember, if you want to excel in your weight loss or athletic performance carbohydrates are key.
As always, if you have any questions, please contact me!
Cynthia Schmeck, ND, MSc, NASM-CPT