1. When you already chugged a bunch
If you chug enough to dilute your body’s natural balance of salt, you can become too low in sodium, a condition known as hyponatremia. Endurance athletes, for example, may be tempted to keep on sipping all throughout a marathon (or after), leading to cell swelling that can cause nausea, vomiting, seizures, and even death. Hyponatremia can also be caused by certain issues with the liver, kidney, heart, or pituitary gland.
2. When you ate a big meal
It’s one of the simplest ways to cut back on a few calories: Drink a glass of water before a meal (or when a craving strikes) and you’ll naturally eat a little bit less since that fluid is already taking up space in your fist-sized stomach. But for the very same reason, drinking too much water before or during a heavy meal can lead to discomfort. Drinking more water may only leave you feeling even more bloated.
3. When your pee is clear
Forget that old “8 glasses a day” rule and instead take a look in the toilet. If you see a light lemonade shade, you’ve reached optimal hydration status. If you see only clear urine in the bowl, you can probably cut back your water intake. Darker yellows can be a sign it’s time to get sipping.
4. When you’re doing a super-intense workout for a long period of time
We lose electrolytes, like potassium and sodium, through sweat. If you’re seriously sweating it out, you’ll need to replace those crucial nutrients, which aren’t found in plain water. Rather than a sugary sports drink, though, you may be able to get the same boost from coconut water, which is naturally high in potassium, magnesium, sodium, and vitamin C without as many calories and with more fiber.
5. When the water has a not-so-sweet secret
No one wants to drink regular water when there are all these flavored bottled varieties to choose from. But flavored waters often rely on zero-calorie sweeteners to add a little something to the plain water taste. Because these sweeteners have been linked to increased hunger and even weight gain in some studies, commercially available flavored waters might do you more harm than good. Instead, try adding your own flavor to tap water by tossing in lemon, lime, cucumber, watermelon, berries, or even herbs.