[header] How to avoid caffeine overdose for athletes [title] Drink plenty of water before you exercise. [step] The amount of water you need varies from person to person, but generally you want to maintain consistent hydration to avoid becoming dehydrated by exercise, especially if you sweat a lot. [substeps] The easiest way to determine whether you're well hydrated is to look at the color of your urine. 
If it's clear, you're well hydrated. The darker your urine, the more water you need to drink.