Welcome! Thomas here.
Green tea will have around 25 mg of a natural form of Caffiene per serving(8oz). there are benefits from caffiene and some hidden dangers. If you are drinking more becuase you are thirsty, that is your body telling you its dehydrated. Caffiene will increase your heart rate, thus increasing O2 exchange and leading in further dehydration, with 8 oz of green tea you would be loosing about 4 oz of water when you urinate from the caffiene alone.
remember this form of caffiene is water based and will not bind to your cells like coffee will. meaning its not the jittery kind of stimulant.
I will-in short, say not to sip on green tea over the day, but try some crystal lite if plain water is getting boring for you.
most humans will require around 96 oz of water per day.
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