By Cmdr. Connie Scott, Navy and Marine Corps Public Health Center
We all know that water is good for us. But do you know just how critical it really is? Consider this – you can survive for weeks without food, but you can only live for days without water.(2, 3)
It’s that important! Water helps replenish fluid loss, regulate temperature, protect organs, keep joints moving, transport other nutrients throughout your body, and eliminate waste.(2, 3) Let’s take a look at your basic hydration needs and ways to determine if you’re meeting them, as well as how your needs increase due to physical activity and tips for preventing dehydration.
Your main source of hydration should always be water. The amount of water that your body needs is based on a variety of factors, two of which are body weight and physical activity.(3) You must meet your hydration needs daily, because your body loses water through regular activities such as sweating, urinating, and even breathing.3 Use the table below to identify your recommended daily hydration needs based on your body weight.1
Body Weight Ounces (oz) per Day
- 120 pounds 60-120 oz/day
- 150 pounds 75-150 oz/day
- 175 pounds 90-175 oz/day
- 200 pounds 100-200 oz/day
- 225 pounds 115-225 oz/day
- 250 pounds 125-200 oz/day
It’s important to note that if you are thirsty, your body is already dehydrated.(1) The best way to determine your hydration status is to evaluate your urine.1 Use the chart below to check the color of your urine and gauge your hydration needs.1 You may need to consume more fluids if your urine is approaching or in the dehydrated color ranges. Consult with a health care provider if you have concerns or are extremely dehydrated.
Hydrating for Physical Activity
If you engage in high-intensity physical activity, you may need additional water to offset your fluid loss.3 Follow these helpful hints to ensure proper hydration before, during, and after physical activity(5):
- Drink 17-20 oz of water 2-3 hours before physical activity
- Drink 7-10 oz of water every 10-20 minutes during physical activity
- Drink 16-24 oz of water for every pound of body weight lost after physical activity
Water is the best option for replacing fluids; however, sports drinks can help replenish electrolytes such as sodium and potassium.5 Only opt for sports drinks before, during, or after high-intensity physical activity exceeding 45-60 minutes and follow these tips(6):
- Select sports drinks with 110 milligrams (mg) sodium and 30 mg potassium per 8 oz
- Consider sports drinks with 200 mg sodium per 8 oz and added electrolytes if you are an excessively salty sweater, meaning you can see or feel salt on your skin when your sweat dries
Tips for Hydrating
You can get water from fruits and vegetables such as oranges and celery, but you get most of it from the fluids that you drink.(2, 3) To help meet your daily hydration needs, follow these tips(1):
- Make hydrating a priority – carry a water bottle to drink on the go
- Choose water over sugar-sweetened, caffeinated, or alcoholic beverages
- Add lemon, lime, or cucumber to your water to enhance the taste
Proper hydration can improve your health, enhance your performance, and replace fluid loss following physical exertion. Remember to meet your hydration needs by drinking water throughout the day. Once you’ve identified your needs based on the information above, pour yourself a glass of water and start drinking to your health!
1 Hydrate. Fitness, Sports and Deployed Forces Support. Commander Navy Installations Command. http://www.navyfitness.org/nutrition/noffs_fueling_series/hydrate/. Accessed February 2015.
2 Water in diet. MedlinePlus. U.S. National Library of Medicine. U.S. Department of Health and Human Services. National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/002471.htm. Updated 19 August 2013. Accessed February 2015.
3 Nutrition for Everyone. Water: Meeting Your Daily Fluid Needs. Division of Nutrition, Physical Activity, and Obesity. National Center for Chronic Disease Prevention and Health Promotion. Centers for Disease Control and Prevention. http://www.cdc.gov/nutrition/everyone/basics/water.html. Updated 10 October 2012. Accessed February 2015.
4 Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Food and Nutrition Board, Institute of Medicine, National Academies. http://www.nal.usda.gov/fnic/DRI/DRI_Tables/electrolytes_water.pdf.
Updated 2005. Accessed February 2015.
5 FitFacts. Healthy Hydration. American Council on Exercise. http://www.acefitness.org/fitfacts/pdfs/fitfacts/itemid_173.pdf.
Updated 2008. Accessed February 2015.
6 Hydrate. Fitness, Sports and Deployed Forces Support. Commander Navy Installations Command. http://www.navyfitness.org/nutrition/noffs_fueling_series/hydrate/. Accessed February 2015.