In a cup of instant sports drink, the solute is the drink powder, while the solvent is the water.
The drink powder, which contains various nutrients and electrolytes, is what you mix into the water to create the beverage. When you add the powder to the water, it dissolves, creating a solution where the components are evenly distributed. The water serves as the solvent because it is the liquid in which the powder dissolves.
This relationship is essential because the effectiveness of the drink is largely determined by how well the solute dissolves in the solvent, allowing for proper hydration and replenishment of electrolytes during physical activities.