We’re all aware that drinking plenty of water is essential, especially in the summer. But how much exactly? When is too much a problem? And how clean is that reusable water bottle…if you haven’t washed it with actual soap and water in days? We asked 98point6’s own Jennifer Rossi, MD, who regularly volunteers as medical support on ultramarathons making sure runners stay safe and hydrated, for some easy tips regarding your water intake this season.


Eight glasses containing approximately eight ounces of water is a good rule of thumb for most, give or take relevant factors like age, weight and activity level. If you embark on a five-mile run in 80-degree heat, it’s likely your body will need more replenishment than average, especially post-workout. Similarly, someone who is nursing and on the move all day in an outdoor theme park would benefit from extra hydration.


Water may not taste as delicious as sweet tea or a sports drink, but it is your body’s preferred method of replenishment. As far as language about added electrolytes and “natural” flavors, most other drinks, even those marketed as “healthy,” may contain additives including artificial sugars or caffeine you don’t necessarily need.


While it’s a fact that caffeinated coffee and tea are diuretics—which may cause you to produce urine more frequently—the current consensus is that both do count towards your liquid intake and neither will dehydrate you, when consumed along with other fluids. But use common sense: if you are going on a hike or spending the afternoon playing volleyball on the beach, 32 ounces of water is still a more sensible choice than an extra large iced coffee.


There is such a thing as overhydration, or water intoxication. This condition occurs when an individual drinks more fluid than their kidneys can excrete, throwing off the sodium balance that’s vital to healthy organ function. Symptoms may include nausea, vomiting, headaches and disorientation before escalating to more serious issues like irregular heartbeat and seizures. Unless you are engaging in serious endurance athletics or suffer from certain health conditions such as Syndrome of Inappropriate Antidiuretic Hormone (SIADH), most of us aren’t at serious risk for overhydration, but everyone should be aware.


Still worried about consuming too much or too little water (which would cause dehydration)? “Drink to thirst,” says Jennifer Rossi, MD, a physician at 98point6. “If you stop being thirsty during or right after exercising, you shouldn’t drink more water.” Assessing the color of your urine can also offer some insight. Dark yellow could indicate you need to drink more; clear may indicate you are drinking too much. Light yellow is ideal.


Here’s the thing: the same germs that thrive when you leave food sitting out, don’t properly clean your utensils or don’t wash your hands after using the bathroom (we know, gross…)—they apply to reusable water bottles. So yes, NOT washing yours frequently (at least daily) and thoroughly, in hot, soapy water, preferably with a bottle brush, can make you sick. “Viruses, bacteria and intestinal parasites can grow in the dirty water,” says Dr. Rossi. “Most of those won’t affect you but some can cause nausea, vomiting or diarrhea. The risk is greater if you share the bottle with someone else.” If you don’t want to stop and wash your container multiple times during the day, purchase and fill a bunch of reusable bottles for daily use and put them in the sink or dishwasher as you empty them.

Got a question or health concern about hydration? Connect with a 98point6 physician on-demand anytime, from anywhere.