Hard charging adults who train with intensity in the weight room and cover long distances running or cycling have greater hydration need than less active people. How much more isn’t well documented, and a study published in the Journal of the American College of Nutrition has interesting findings for those who carry around a gallon jug.
Researchers measured the daily fluid intake of 35 healthy males for a week before increasing their intake of water or water and other beverages by 22%. Those other options included no calorie soda and orange juice. But their 24-hour hydration status didn’t change over that time period regardless of beverages consumed. The basic rule of thumb is to drink when thirsty.