Which are common signs of dehydration during exercise?

The presence of thirst, fatigue, dizziness, and decreased performance as signs of dehydration during exercise is well-supported by research in exercise physiology. Thirst is the body's natural signal indicating that fluid intake is needed. Fatigue occurs as the body becomes dehydrated and struggles to maintain optimal physiological functions, including temperature regulation and cardiovascular responses. Dizziness can result from lowered blood volume and circulation efficiency, affecting blood pressure and oxygen delivery to the brain. Decreased performance comes about due to reduced endurance, strength, and overall athletic function, which are all critically impacted by inadequate hydration levels.

In contrast, excessive sweating, high energy, and calmness do not accurately represent dehydration; in fact, high energy and calmness are typically associated with proper hydration and optimal physical condition. Increased urine output, heightened concentration, and energy would be typical of a well-hydrated athlete rather than someone who is dehydrated. Lastly, immediate muscle growth and stronger endurance are not typically recognized signs of dehydration, as hydration is crucial for recovery and optimal muscle function.