I’ve written about this before. I tell my clients to stay hydrated, rather than asking them to drink “extra water” after a massage to “flush the toxins out.”
Water makes physiological processes, especially the brain, work better, so getting enough is important. Whatever measure you use – a gallon a day, half your body weight in ounces, until your pee is clear – most of us don’t drink enough, and we need extra to make up for sweating, diarrhea, etc.
Now New York Times health writer Gretchen Reynolds addresses the issue, interviewing an expert.
What no persuasive science has shown is that massage releases toxins that then need to be flushed away. “I am unaware of any studies that support that idea,” said Dr. Adam Perlman, the executive director of Duke Integrative Medicine in Durham, N.C., who has conducted studies of massage. “Of course, I’m also unaware of any studies that disprove the idea.”
“It’s possible that there might be an increase in certain metabolites after a massage,” Dr. Perlman said. But these molecules are byproducts of normal metabolic activity, are not toxic, he said, and do not need to be flushed away.
As for the widespread belief that massage can help to remove lactic acid from sore muscles, “there’s pretty good evidence now that lactic acid is not harmful,” Dr. Perlman said. And a 2010 study found that postexercise massage didn’t remove lactic acid effectively anyway.
And…there is such as thing as getting too much water, as seen in the comments. It can cause seizures and even death.
So seek an ongoing balance between “dehydrated” (not enough), “juicy” (just right), and “floating” (too much).