If you are doing any outside activities in the sunshine your body will be producing vitamin D. To preserve this build up, wait to shower so it can be absorbed through the skin and not washed off. Dr. John J. Cannell explains this in the 8-31-09 issue of First magazine saying if you must freshen up, use water and hold off on the soap until the evening. Vitamin D increases immunity, increases energy, boosts your mood, and (best of all!) melts body fat.