Drinking water after a massage is often recommended by massage therapists and other health care practitioners, for a variety of reasons. In fact, drinking water in general is a good idea, as the body benefits from proper hydration, and consuming water will help the kidneys and other organs process the various substances which move through the human body on a regular basis. Drinking water before a massage is also highly recommended, as it will make it easier for the massage therapist to perform deep work by hydrating the muscles so that they are easier to manipulate.
There are primary reasons for people to drink water after a massage. The first has to do with substances released by the muscles as the massage therapist manipulates them, and the second has to do with ensuring that the muscles of the body are properly hydrated.
In the case of the first reason, drinking the water helps the body flush out any accumulated materials in the muscles which were released during the massage. Especially in the case of deep tissue massage, massage stimulates circulation in the body while expressing water, salt, and other minerals from the muscles, and circulation is designed to carry away waste materials generated by cells. By providing the body with plenty of water, massage clients can help sweep away these waste materials; otherwise, they might build up, causing muscle aches and soreness after a massage.
In the case of lymphatic massage, drinking the water is especially important, as the stimulation of the lymphatic circulation system can generate a large release of wastes in the body. If one thinks of the lymph system as the sewer pipes of the body, collecting unwanted waste material and carrying it away for disposal, lymphatic massage is like a drain cleaner, so water helps flush the drain, in a sense.
Most importantly, people should drink water because massage can be dehydrating. The manipulation of the muscles depletes them of water, and also moves the fluid in the interstitial spaces between the muscles around. By drinking water, people can rehydrate their muscles, reducing the potential for pain and soreness in the days following a massage. For the same reason, people drink water after exercise and other forms of exertion, because when the muscles are worked, they lose water and electrolytes.
Many people also like to drink a glass of water after a massage because it helps bring them back down to earth. After a massage, people can feel a bit spacey and disoriented, so having a glass of water while sitting on the massage table can help bring the body and mind back to the present, and it gives the client time to slowly return to the real world.