I think this is really a medical question, which is why I put it in S&T. According to some doctors, Americans really bathe too much. Twice a day is rather excessive, they say. So my question then, is how much is ideal? Once a day seems about right. I know when I was in high school, we had a health class. And they said minimally, every other day (although I have to tell you, I think some of the boys there didn't even do that). Not to get gross, but as a small child, my mother bathed me once a week (every Saturday, naturally). So just from a medical standpoint: What amount is ideal?
Excessive bathing in water that is too hot has been linked to male infertility. I personally take a quick shower every two to three days. On a Sunday I have my long bath.
Dr. Elaine Larson works at Columbia University School of Nursing and specializes in infectious diseases. In a recent interview with Time Magazine, she said that you don’t need to be taking daily showers to keep your skin clean. “People think they are showering or to be cleaner, but bacteriologically, that’s not the case,” she explained. Taking too many showers can actually rob your skin of its natural oil (sebum) and can dry out the skin, risking more infection from the cracks that can form in the skin’s folds. According to Dr. C Brandon Mitchell, who works at George Washington University as a professor of dermatology, all you really need is about two showers per week. http://www.huffingtonpost.com/michael-lazar/you-dont-need-to-shower-d_b_9677234.html