H2O - water

Water - absolutely necessary for life and for exercise.

Aim to drink 8 glasses a day when not working out.  On days you will work out, try to drink 1-2 glasses (8 oz) 1 - 2 hours before the workout.  You can drink water during the workout, especially if it's hot and humid.  After the workout, try to drink another 1-2 glasses.  Staying hydrated is very important and it does affect your performance.