Fastest way to get dehydrated? Not asking so I can do it, I'm trying to avoid it! I play sports & am always busy on the go, also drink a lot of coffee

Water replacement. Fastest means dehydration illness nausea vomiting diarrhea. Loss of water unable to replenish. Can happen in extreme athletics in severe hot weather conditions. Essential that you follow your thirst mechanism. Hydrate before and after. Color of urine good clue closer it appears to water the closer you are to repleated.