On the "too much water" issue — sure, it’s possible, and it can lead to hyponatremia . Bad.
More generally, the Institute of Medicine’s recent guidelines on water intake are interesting. An excerpt from the linked article about the guidelines:
****
True or false?
- Health and nutrition experts recommend drinking eight or more 8-ounce servings of water daily.
- You should not wait until you’re thirsty to drink water. By the time you feel thirsty, you have lost a significant amount of your total body water composition.
- Caffeinated beverages such as coffee, tea, and cola, along with alcoholic beverages, can cause dehydration by lowering the net total of hydrating beverages such as water.
- Because the thirst mechanism becomes blunted with age, older people, in particular, need to make a conscious effort to drink eight glasses of water daily.
- For men, an average of 16 cups of water a day is adequate; for women, an average of 11 cups.
****
The basic message of the guidelines is that most Americans consume plenty of water simply by drinking when they are thirsty and eating a normal diet. My own opinion is that excessive water intake will not help PE in any way.