How much water should you drink a day? You probably know that it's important to drink plenty of fluids when the temperatures soar outside. But staying hydrated is a daily necessity, no matter what the thermometer says. Unfortunately, many of us aren't getting enough to drink, especially older adults. Older people don't sense thirst as much as they did when they were younger. And that could be a problem if they're on a medication that may cause fluid loss, such as a diuretic.
Benefits of drinking water
Water keeps every system in the body functioning properly. The Harvard Medical School Special Health Report 6-Week Plan for Health Eating notes that water has many important jobs, such as:
- carrying nutrients and oxygen to your cells
- flushing bacteria from your bladder
- aiding digestion
- preventing constipation
- normalizing blood pressure
- cushioning joints
- protecting organs and tissues
- regulating body temperature
- maintaining electrolyte (sodium) balance.
Giving your body enough fluids to carry out those tasks means that you're staying hydrated.
If you don't drink enough water each day, you risk becoming dehydrated. Warning signs of dehydration include weakness, low blood pressure, dizziness, confusion, or urine that's dark in color.
So how much water should you drink? Most people need about four to six cups of water each day.
How much water should you drink a day?
The daily four-to-six cup rule is for generally healthy people. It's possible to take in too much water if you have certain health conditions, such as thyroid disease or kidney, liver, or heart problems; or if you're taking medications that make you retain water, such as non-steroidal anti-inflammatory drugs (NSAIDs), opiate pain medications, and some antidepressants.
How much water a day should you drink if you fit into that category? There's no one-size-fits-all answer. Water intake must be individualized, and you should check with your doctor if you are not sure about the right amount for you.
But even a healthy person's water needs will vary, especially if you're losing water through sweat because you're exercising, or because you're outside on a hot day. If you're wondering how much water you should drink on those occasions, speak with your doctor, but a general rule of thumb for healthy people is to drink two to three cups of water per hour, or more if you're sweating heavily.
Tips for avoiding dehydration
It's not just water that keeps you hydrated. All beverages containing water contribute toward your daily needs. And it's a myth that caffeinated beverages or those containing alcohol are dehydrating because they make you urinate. They do, but over the course of the day, the water from these beverages still leads to a net positive contribution to total fluid consumption.
Of course, there are many reasons why water is still the better choice. Remember, sugary drinks can lead to weight gain and inflammation, which can increase your risk for developing diseases such as diabetes. Too much caffeine can give you the jitters or keep you from sleeping. And, alcohol intake should be limited to one drink per day for women, and 1-2 drinks per day for men.
To ward off dehydration, drink fluids gradually, throughout the day. An easy way to do this is to have a drink at each meal, as well as socially, or with medicine.
Summer is right around the corner … and with it, summer activities, warmer temperatures and an increased risk for dehydration. Here are some tips to help you make sure you are drinking enough fluids to maintain good levels of hydration.
You are probably all aware of the “cardinal rule” that says adults should drink six to eight 8-ounce glasses of water per day. The truth is, this is an estimate and the actual amount you should be drinking per day can vary quite significantly. There are multiple factors that can impact how much water you should be drinking.
WeightYour weight is one variable that changes the amount of water you should be drinking. To help you establish a baseline, you can use the following rule-of-thumb equation described in U.S. News & World Report.
In short, the equation tells you to take half your body weight, and drink that amount in ounces of water. In the example, notice that you should be drinking more than 12 glasses of water, not eight!
ExerciseYour exercise habits affect the amount of water you should be drinking, as well. The American College of Sports Medicine recommends adding 12 ounces of water to your daily intake for every 30 minutes that you plan to work out.
If you are exercising outside and it is very hot, you may need to add more.
There are several special considerations to maintaining a healthy hydration level. If you are pregnant or breastfeeding, you need to increase your fluid intake by 24 to 32 ounces depending on how much you weigh, according to the American Pregnancy Association. It is also important that you get a lot of your hydration from water. If you are primarily drinking sodas or caffeinated beverages such as coffee or tea, you do not get as much “bang for your buck” when it comes to fluid intake (i.e., they don’t “count” as much).
Rules of thumbThe good news is there are some fairly easy rules of thumb to follow when it comes to hydration. One of the important ones is to pre-hydrate. In other words, drink BEFORE you start feeling thirsty, or BEFORE you do an activity. Going running? Drink several glasses of water before you start. Thirst is actually a sign of dehydration, so if you feel thirsty, you have some catching up to do!
Also, monitor your urine. If you are adequately hydrated, you should be urinating about once every two to four hours, and your urine should be colorless or a very pale yellow (the color of hay or lighter). If it is darker than that, you haven’t had enough fluid. Headaches and dizziness are a late sign of dehydration. If you start experiencing those, you really need to up the water intake, and quickly.
Dehydration can turn a fun summer activity into an unpleasant experience at best, or a trip to the emergency room at worst.
Don’t wait until it’s too late. Bring water bottles with you, and keep yourself and your family hydrated during your summer fun!
More info:
- Physical activity programs from the university’s Healthy for Life Wellness program for faculty and staff. These include the Million Step Pedometer Program and the Ride to Wellness Odometer Program, which provide tools to help you get walking and biking.
- Download walking maps/trails for each campus.
Sources cited:
- Buffardi, Danielle (2012, November 13). “Staying Hydrated And Nourished During Pregnancy,” American Pregnancy Association. Retrieved at //www.americanpregnancy.org/pregnancyblog/2012/11/staying-hydrated-and-nourished-during-pregnancy/.
- Casa, Douglas, Clarkson, Priscilla and Roberts, William (2005). American College of Sports Medicine Roundtable on Hydration and Physical Activity: Consensus Statements, American College of Sports Medicine. Retrieved at //www.acsm.org/docs/publications/Roundtable%20on%20Hydration%20and%20Physical%20Activity.pdf?sfvrsn=0.
- Elkaim, Yuri (2013, September 13). “The Truth About How Much Water You Should Really Drink,” U.S. News & World Report. Retrieved at //health.usnews.com/health-news/blogs/eat-run/2013/09/13/the-truth-about-how-much-water-you-should-really-drink.
About the author: Jennifer is a Clinic Supervisor for Mizzou Therapy Services (Rangeline location) and a board-certified specialist in orthopedic physical therapy. She is also CAP certified in women’s health physical therapy. She has five years of experience in physical therapy and earned her Master’s degree from Texas State University, her doctorate from Massachusetts General Hospital Institute for Health Professions, and completed an orthopedic residency through Evidence in Motion.