What is the effect of pre-exercise dehydration on performance?

Pre-exercise dehydration significantly decreases both thermoregulation and athletic performance. When the body is dehydrated, its ability to regulate temperature effectively is compromised. This is critical during physical activity, as optimal thermoregulation allows for better performance by preventing overheating and ensuring that muscles and other physiological processes function properly.

Additionally, dehydration can lead to a reduction in blood plasma volume, which impairs cardiovascular efficiency. This negatively affects oxygen delivery to the muscles, leading to quicker onset of fatigue and reduced stamina. Studies consistently show that even mild dehydration can result in diminished exercise performance, particularly in endurance sports, affecting strength, overall endurance, reaction times, and cognitive functions.

In contrast, improvements in stamina and energy levels are typically associated with adequate hydration and proper nutrition. Therefore, the notion that dehydration would enhance performance or thermoregulation directly contradicts established sports science principles. Thus, it is well-supported that pre-exercise dehydration has a detrimental effect on both thermoregulation and performance.