As a massage therapist, one of the main things my clients ask after a session is why I ask them to drink water. On average, the human body is composed of 57-60% water. Why so much? Our body uses water for everything. First, our brain and nervous system run on electrical impulses. One of the best conductors for electricity on Earth is water. Therefore, in order for all your nerves to fire properly, and for your brain to receive these impulses quickly, it is essential that your body not be dehydrated. Also, water helps the kidneys and liver to flush toxins out of the body. During a massage, metabolic waste.