4. Discussion
non-homeostatic thirst, thirst, thirst behavior, perceptual thirst, pain, hypohydration, mass loss
The objective of this study was to determine the impact of fluid availability on fluid intake behavior and perceptual thirst and GI discomfort measures during moderate intensity exercise. The main finding of the current study demonstrates that increasing fluid availability when drinking AL resulted in significantly greater fluid intake over a 10 km run. Importantly, the increase in fluid volume did not result in an increase in GI discomfort, indicating that AL fluid availability may be a practical and ideal hydration strategy during exercise. The literature has established that hypohydration can negatively influence aerobic exercise performance [Current results indicate that the amount of fluid consumed had no significant effect on the sensation of thirst or GI discomfort. This is contrary to previous studies that showed a decreased sensation of thirst and increased abdominal discomfort when participants drank more fluid during exercise [Armstrong et al. summarize thirst behavior into two main categories that affect thirst: homeostatic thirst and non-homeostatic thirst [Another factor that may influence fluid consumption behavior is the gastric emptying rate. As fluid is ingested, the pyloric sphincter regulates the rate at which fluid leaves the stomach and enters the rest of the GI tract. The timing and volume of fluid consumption can exceed the stomach’s capacity to distribute fluid, thus, resulting in discomfort and pain. Because of this, even though the sensation of thirst may be present, gastric emptying rates only allow for the consumption of a limited amount of fluid before the stomach feels full [The previous literature has indicated that maintaining a body mass loss <2% is ideal for optimal exercise performance [