Carbohydrates (also called carbohydrates or sugars) constitute the main source of metabolic energy for the human body. They are essential for the functioning of the central nervous system and muscle performance.

Although the body has backup pathways to produce glucose (gluconeogenesis), the vast majority of circulating sugars come from food and the breakdown of hepatic and muscle glycogen reserves.

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1. Structural Classification of Carbohydrates

From a biochemical standpoint, there are two main categories of carbohydrates based on their molecular complexity:

A. Simple Carbohydrates (Monosaccharides and Disaccharides)

Simple sugars have a small molecular size. They are responsible for the sweet taste of foods. The most notable ones are:

• Glucose: The body's basic sugar (or dextrose).
• Fructose: Naturally present in fruits.
• Sucrose: The classic table sugar.
• Lactose: The sugar specific to dairy products.

B. Complex Carbohydrates (Polysaccharides)

They are made up of long chains of glucose molecules. The main representative is starch, the energy storage form of plants. It is found mainly in:

• Cereals: Wheat, rice, oats, quinoa, etc.
• Legumes: Lentils, beans, chickpeas.

Technical note: Although lacking a sweet taste, complex carbohydrates cause a rise in blood sugar after digestive hydrolysis, just like simple sugars.

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2. The Special Case of Dietary Fibers

Fibers constitute a specific group of polysaccharides that are not digestible by human enzymes.

Physiological properties of fibers:

• Glycemic modulation: They slow down the absorption of sugars in the intestine, avoiding insulin spikes.
• Digestive health: They optimize intestinal transit and feed the flora (prebiotic effect).
• Caloric impact: Being non-assimilable, they have virtually no direct impact on blood sugar.

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3. Metabolic Functions and Recovery

Whether simple or complex, all assimilable carbohydrates have a single metabolic purpose: the production of Adenosine Triphosphate (ATP).

Key roles in the body:

• Immediate energy: Support for biological functions (thermogenesis, basal metabolism).
• Sports performance: Exclusive fuel for high-intensity efforts (glycolytic pathway).
• Recovery and Anabolism: The presence of carbohydrates post-exercise promotes the secretion of insulin, a key hormone for the transport of amino acids to muscle cells and the resynthesis of glycogen.

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Conclusion: Carbohydrate management is the main lever for modulating available energy and optimizing muscle regeneration.