Why do the massage therapist keep telling me to drink lots of water?

Your muscles are a 'store house' for chemicals, toxins, vitamins, etc. When you receive a deep tissue massage, these substances are released back into the bloodstream in concentrated form.

Following a structural massage session, water consumption can help flush them out of your system.  This will aid in the prevention of sore muscles, headaches, cramping, nausea or diarrhea after a deep tissue session.

Also, if you drink water Before a massage, this can help loosen your muscles, resulting in a more enjoyable session.