Sometimes I am amazed at what gets published in reputable journals. This study monitored the hydration status of 14 elite Kenyan distance runners over 5 days.
Guess what they found out? Kenyans drink!
These results demonstrate that elite Kenyan endurance runners remain well hydrated day-to-day with an ad libitum fluid intake; a pattern and volume of fluid intake that is consistent with previous observations of elite Kenyan endurance runners.
Elite Kenyan Endurance Runners are Hydrated Day-To-Day with Ad Libitum Fluid Intake Medicine & Science in Sports & Exercise