What is a key benefit of proper hydration during exercise?

Proper hydration during exercise is crucial for maintaining optimal performance and enhancing endurance. When the body is adequately hydrated, it can regulate temperature more effectively, which is fundamental during physical activity. Dehydration can lead to decreased blood volume, reducing the heart's ability to pump oxygenated blood to the muscles. This can result in fatigue, decreased endurance, and impaired performance.

Additionally, hydration aids in the transportation of nutrients to muscles and facilitates the removal of metabolic waste. When hydration levels are sufficient, athletes can sustain their energy levels longer, which is vital for both endurance activities and high-intensity workouts. Thus, the key benefit of proper hydration is its direct contribution to enhanced endurance and performance.

The other options do not directly relate to hydration's primary role during exercise in the way that enhancing endurance does. While hydration may indirectly influence reaction time or the risk of injury, its most significant and measurable benefit is seen in how well a person can perform and endure through exercise.