The fitness world is filled with myths and misconceptions. Somewhere along the way somebody said that 1 gallon of water per day is a good rule to follow and everyone ran with it. That somebody was an idiot. The reason I say this is because it’s an arbitrary amount no different than telling anyone who wants to lose weight that they should eat less than 2000 calories per day. Just like caloric intake needs, water intake needs vary greatly from person to person. One person might need 2 gallons per day and someone else might need a half gallon. There are so many factors that play into water intake that giving some random amount as a blanket rule is just ridiculous.
The problem is people think “It’s water. It’s good for you. The more the better.” Unfortunately for the 1000’s of tiny fitness girls slamming back their gallon of water every day, too much water hurts performance and is actually unhealthy. Yes that’s right, too much water is bad for you.
This is a fancy medical term for drinking too much water. The way this works is pretty simple if you just take a second to think about it. Imagine you drink water to the point that you have to use the bathroom frequently, say every 45 minutes. What comes out through urination? It’s not just water. Potassium, sodium, and magnesium are lost through urination. These are the electrolytes that allow your brain to send nerve impulses. Nerve impulses are pretty important because without them working correctly your brain can’t communicate with areas like skeletal muscle and your heart. They also help maintain important fluid levels in specific areas of the body.
So when you drink excessive amounts of water you flush out key electrolytes and unless they are replaced effectively, which most of the time they aren’t, you end up with low levels of sodium (hyponatremia), potassium (hypoalkalemia), magnesium (hypomagnesemia), and others. It is possible in extreme cases to see people actually die from excessive water intake. This isn’t a scare you via death article but just shows that if something at the extreme end can cause death then somewhere along the way bad things have already begun in the body.
Well in general the symptoms may just be written off as not feeling great. Most people will never think it may be too much water and low levels of electrolytes causing the issue. Some symptoms of electrolyte depletion are fatigue, weakness, headache, decline in cognitive function, and muscle spasms/cramps. Have you ever had a really tough workout with excessive sweating and following the session end up with muscle cramps/spasms? Sweat a ton, drink tons of water, muscle cramps and spasms happen. The reason for this is not dehydration, it’s a loss of electrolytes which water doesn’t replace. This is literally the science behind how Gatorade was invented.
So what happens when you aren’t sweating heavily but you are urinating excessively from high water intake? The same thing. Electrolyte depletion. For the bodybuilders and physique athletes out there this also makes getting and maintaining a pump more difficult as well as destroys muscle fullness and vascularity. So along with fatigue and weakness it will actually cause you to look flat and soft. Blood volume gets messed up. Electrolytes that help keep a certain amount of fluid in the muscle tissue aren’t available and you flatten out.
How much water should you drink?
Simple answer: drink as much as is needed to urinate roughly every 2 hours and your urine should be pale/light yellow. This is a good guideline because water intake needs can change day to day based on energy expenditure and the amount of sweating. On a day where you run outside in 90 degree heat you will need more water than on a day when you trained with air conditioning or didn’t train at all. Your body tells you how much water you need. Listen to it.
I have so many people, especially women, in the fitness world who tell me they’re drinking a gallon a day and are in the bathroom every 45-60 minutes. The reason women are more susceptible to this issue is they generally have lower body mass, metabolic rate, and sweat less than men which means their intake needs are going to be significantly less.
Drinking a ton of water doesn’t make you healthier, stronger, or leaner. Drink enough to stay well hydrated and no more.