What is a primary effect of dehydration on athletic performance?

Dehydration has a significant negative impact on athletic performance primarily by leading to decreased performance. When the body is dehydrated, it can lose as little as 2% of its body weight in fluids, which can noticeably affect endurance, strength, and overall physical capabilities. Dehydration impairs the body's ability to regulate temperature, reduces blood volume, and ultimately compromises cardiovascular performance, leading to fatigue, weakened muscle function, and impaired coordination. These physiological changes can drastically hinder an athlete's effectiveness during physical activity, making it essential to maintain proper hydration for optimal performance.

In contrast, options like increased energy levels, improved cognitive function, and enhanced thermoregulation do not accurately reflect the effects of dehydration. Rather, dehydration can cause fatigue and decreased alertness, further exacerbating performance issues. Thus, the primary effect is a marked decrease in athletic performance due to the body’s compromised physiological processes.