The 8x8 rule holds that everyone (male, female, all body types, all situations of exertion and temperature) should drink 8 cups of WATER daily. The reality is, different people have different needs and in different situations, and the amount of liquid you need each day includes not just water, but the water you get from coffee, milk and other beverages. Nowhere does the story suggest anyone should drink double the 8x8 rule. Hope that helps clear things up, and thanks for asking — it is a lot to absorb, and as Farrell says at the end, for most people in most situations, thirst and common sense will be a sufficient guide.