Which nutrient is essential for energy metabolism and is often included in sports drinks?

The essential nutrient for energy metabolism that is commonly included in sports drinks is carbohydrates. Carbohydrates are the primary source of energy for high-intensity workouts and during prolonged physical activities. They are quickly metabolized by the body to provide glucose, which fuels muscle contractions and maintains energy levels.

While electrolytes like sodium and potassium play critical roles in hydration and maintaining nerve and muscle function, they don't directly contribute to energy metabolism in the way carbohydrates do. Instead, their primary function is to help manage fluid balance, which is important during strenuous exercise but does not provide the immediate energy needed for performance.

Proteins and fats, though vital for overall nutrition, serve different purposes in the body. Proteins are primarily involved in muscle repair and growth, while fats serve as a longer-term energy source and are metabolized at a slower rate. Thus, in the context of sports drinks specifically designed for energy metabolism during physical activity, carbohydrates are the nutrient that meets this need effectively.