How much work capacity is lost at 2% dehydration?

The correct choice indicates that at a level of 2% dehydration, between 5% to 8% of work capacity can be lost. This information is crucial as even a small amount of dehydration can significantly impair physical performance.

At 2% dehydration, an individual's physiological function begins to decline, affecting endurance, strength, and overall exercise performance. This is primarily due to a decrease in blood volume, resulting in compromised cardiovascular efficiency and increased perceived effort during physical tasks. Additionally, dehydration can lead to impaired thermoregulation, affecting body temperature control and leading to quicker onset of fatigue. Understanding this impact reinforces the importance of adequate hydration for both optimal performance and health.

In terms of the other choices, the range of 1-3% does not adequately capture the performance drop that occurs at 2% dehydration, while the higher values of 12-15% and 20-23% correspond to more severe dehydration levels that lead to significantly greater declines in work capacity. The effects observed around 2% serve as an important benchmark for athletes and trainers to monitor hydration status and maintain performance levels.