What percentage of heat is lost through evaporation during exercise?

During exercise, the human body primarily regulates its temperature through the mechanisms of perspiration and evaporation. Evaporation is a key process by which the body cools itself, as sweat evaporates from the skin's surface, leading to a significant loss of heat.

Research indicates that between 65% to 80% of the heat generated during exercise can be lost through evaporation, depending on various factors such as environmental conditions, intensity of exercise, and individual physiology. The correct answer reflects this understanding, showcasing that evaporation serves as one of the most critical means for thermoregulation during physical activity. In this context, the given percentage of 65% highlights a substantial estimate that aligns well with the physiological principles of heat loss during exercise. This emphasizes the importance of maintaining adequate hydration to support the evaporation process and, consequently, effective heat regulation while exercising.