According to Wikipedia: "Water intoxication can be prevented if a person's intake of water and electrolytes closely matches his or her losses. The body's regulatory mechanisms provide a very generous margin of safety if the two are imbalanced, but some extreme activities (such as heavy, prolonged physical exertion), as well as disease states, can overwhelm or impair these mechanisms.""Can you hold "it" in for a long time? We're having you drink water every 15 minutes! And the last person to go to the bathroom wins the Wii!