With 5 percent body weight loss due to dehydration, work capacity can be decreased by as much as:

When an individual experiences dehydration that leads to a 5 percent loss of body weight, this significantly impacts physical performance and work capacity. Research shows that even a small percentage of dehydration can reduce athletic and physical performance. Specifically, a 5 percent decrease in body weight due to dehydration can lead to a decrease in work capacity by up to 30 percent. This decrease is attributed to the body's diminished ability to thermoregulate, coordinate muscle movement, and maintain endurance.

Dehydration affects cardiovascular function by increasing heart rate and reducing stroke volume, leading to compromised efficiency during physical activities. This physiological strain can be so significant that individuals may find themselves unable to perform at their optimal levels, thus resulting in approximately a 30 percent decline in work capacity. Understanding this relationship is essential for maintaining hydration and optimizing performance in physically demanding situations, such as those faced by firefighters.