By now you may have heard that the 8x8 water rule (8 ounces, 8 times a day) has been debunked. The truth: It’s basically an arbitrary guideline that dates back to 1945 and there’s no real science behind it.
Feeling duped? Don’t—it turns out the science surrounding water isn’t all that advanced in 2015, either. “Water is absolutely crucial for the body, but it’s a forgotten nutrient in science. We don’t have the best tools for measuring how much we drink, and so the literature around hydration is about as advanced as smoking research was in the 70’s,” says Stavros Kavouras, Ph.D., an associate professor at the University of Arkansas who studies hydration.
Here’s what researchers have sorted out: water (which makes up around 50-60 percent of your insides) cushions and lubricates your joints, and keeps the body running by regulating body temperature, aiding digestion, and eliminating waste through sweat and numbers 1 and 2. (Still, 37 percent of adults drink fewer than three cups a day, and seven percent don’t drink any water, according to the CDC.) There are a few other critical, science-backed reasons we’re on team hydration, too: