You should be consuming about 3 liters of liquids (not necessarily water) per day for an average male: http://www.mayoclinic.com/health/water/NU00283 http://www

You should be consuming about 3 liters of liquids (not necessarily water) per day for an average male: http://www.mayoclinic.com/health/water/NU00283 http://www.mayoclinic.com/health/water/NU00283 This is highly variable, of course. If you go out an run a 45 minute 10k, then you're going to need a lot more water than someone who has done minimal physical activity all day.