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Too Lazy To Live? Nutrition, Vitamins, Exercise, Wellness
Why are carbohydrates important for exercise?
Carbohydrates are the single most important source of energy for athletic performance. They are a rapid source of fuel to the working muscle and are burned efficiently with or without the presence of oxygen.
Carbohydrates are oxidized (broken down) three times faster than fat and are the predominant energy source for fueling both aerobic and anaerobic activity.
Carbohydrates are stored in the body’s muscle cells as glycogen and can provide the athlete with approximately 2,000 to 2,400 calories of energy.
Eating sufficient amounts of carbohydrate in the daily diet (more than 50%) will help the body preserve its muscle protein and assist in the use of fat as a fuel. Consuming low-carbohydrate diets is not recommended, as they cause a decrease in muscle glycogen stores.
This glycogen decrease can lead to premature muscle fatigue during exercise and may result in the body using its muscle protein as a source of energy. Athletes who need to lose weight will discover that carbohydrates aid in the fat-burning process, as fat burns in a carbohydrate flame.
Quick Fact
Very high-carbohydrate diets can raise blood triglyceride levels, leading to increased fat stores and weight gain
Carbohydrates are the key to muscle contraction, nerve conduction, and brain function. Carbohydrates should make up 50% or more of an athlete’s daily food intake; anything less than 50% can compromise muscle strength, muscle endurance, power, mental focus, and recovery. Carbohydrates are essential before, during, and after exercise in order for the athlete to attain optimal performance and recovery.
The average athlete has the capacity to store approximately 400 to 500 grams of carbohydrate as glycogen in the body. Glycogen is stored in the body at three sites: muscle cells, liver, and blood. Muscle cells are the largest source, storing approximately 300 to 400 grams (1,200 to 1,400 kcal).
The liver is the second largest storage site, containing approximately 75 to 100 grams (300 to 400 kcal). Blood is the smallest site, circulating approximately 25 grams (100 kcal). Training and carbohydrate loading positively influence the amount of muscle glycogen stored.
The glycogen that is used during exercise is specific to the muscle being used. Although there are 300 to 400 grams of total glycogen stored throughout the muscles, only a certain percentage can be used, depending on which muscles are activated.
A runner, for example, will use the glycogen stores in the muscles of the lower extremities (hamstrings, calves, and quadriceps), whereas the glycogen in the upper extremity muscles (biceps, triceps, shoulders, and back) will be used only marginally.
Carbohydrates should make up 50% or more of an athlete’s daily food intake; anything less than 50% can compromise muscle strength, muscle endurance, power, mental focus, and recovery
Terms:
Oxidized – A chemical reaction with oxygen.
Aerobic – In the presence of air or oxygen.
Anaerobic – In the absence of air or oxygen.
Glycogen – The major carbohydrate stored in animal cells, mainly in the muscle cells and some in the liver. Glycogen is converted to glucose and released into circulation, as needed, by the body.
Nerve conduction – The transmission of impulses throughout the nerves in the body.
Carbohydrate loading – A method of increasing – a cell’s glycogen content beyond its usual capacity.
