The Macronutrients
An active lifestyle, including sports and exercise, requires that you choose the right types and amounts of foods to replace fuel stores that you burn for energy. This requires a sensible approach to planning your diet by consuming a wide variety of foods in moderate amounts for the full spectrum of nutrients they provide. Eating a variety of foods at meals and snacks allows nutrients to work better together.
As discussed in Unit 2, food choices should be wholesome, not coming from a large amount of processed foods which lack nutrients. Other considerations for food choices require a closer look at carbohydrates, proteins, and fats, or macronutrients, meaning the primary nutrients in your diet required in the greatest amount. We will discuss each nutrient and its characteristics in terms of energy and performance for athletes, and people interested in fitness.
Carbohydrates
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These are the foundation of an optimal diet for athletes. Foods that include carbohydrates are grains, fruits, and vegetables, also milk and yogurt. Carbohydrates perform several important functions for an athlete. They are a quick source of energy. Most importantly though, carbohydrates replenish muscle and liver glycogen stores. Glycogen is the body’s storage form of carbohydrates and is an essential fuel for athletes. Glycogen is stored mostly in the muscles and liver.
The quality of the carbohydrates is essential towards storing glycogen. Simple and refined sources of carbohydrates are not as effective as wholesome, complex sources. Wholesome carbohydrates provide vitamins, minerals, and fiber, while refined carbohydrates are processed foods with a much lower nutrient content.
Carbohydrates can also be categorized as to how they affect blood sugar levels. The ranking system that describes the blood glucose profile of a food is referred to as the glycemic index. In this system, fifty grams of pure glucose is the reference point, and is designated a glycemic index of 100; that’s your starting point. All other sources of carbohydrate are tested in fifty gram doses and compared to glucose. High glycemic foods have a glycemic index greater than seventy, moderate fifty to seventy, and low glycemic foods score less than fifty. Use the following tutorial to further explore the use of the glycemic index.