It’s no secret that drinking plenty of water is important for good health. Unfortunately, we often minimize just how important it really is, especially since the human body is made up of 60% water. According to the U.S. Geological Survey, the brain and heart, the lungs, and the kidneys and muscles are composed of 73%, 83%, and 79% water, respectively.
All that water is responsible for a number of critical functions, including:
- Acting as a shock absorber in the brain and spinal cord
- Creating saliva and tears
- Delivering oxygen throughout the body
- Keeping mucous membranes moist
- Lubricating joints
- Providing cells with hydration needed for their reproduction and survival
- Regulating body temperature through sweat
- Removing waste products from the body (29)
Health benefits of drinking water
Staying hydrated ensures that the body can carry out all of these critical functions. In addition to assisting in key body functions, drinking plenty of water can provide a number of health benefits, including supporting digestion and metabolism, enhancing physical performance, promoting weight loss, and protecting cognitive health.
Drinking water with a meal promotes the secretion of gastric acids that help break down food you eat. (16) Water also helps dissolve water-soluble vitamins, including vitamin C and the B vitamins, and transport them to the rest of your body for use. (20)
Additionally, making sure you get enough water can help prevent and relieve constipation. (4)(6) One way it accomplishes this is by enhancing the action of fiber consumed in the diet, increasing stool frequency in individuals suffering from functional constipation. (3)
Research has shown that water intake can increase your metabolism. One small study involving 14 healthy men and women found that drinking just 17 ounces of water increased metabolic rate by an average of 30% for upwards of an hour, peaking at 30 to 40 minutes after drinking. (7) These metabolic benefits may also play a role in enhancing exercise performance and weight loss.
Enhances physical performance
Making sure you’re sufficiently hydrated during your workout is important, particularly if you participate in endurance activities such as marathons or dynamic workouts such as high intensity interval training (HIIT). Drinking enough water during exercise can have a positive effect on your performance by improving blood volume, cardiac output, muscle blood flow, and skin blood flow. Research also reports that physical performance drops with even modest dehydration, approximately 2% of your body mass. (18)(19) That’s key since athletes can lose 6 to 10% of their body weight via sweat during a single workout. (22)
Promotes weight loss
Studies show that drinking water can trigger thermogenesis (the production of heat in the body), thus enhancing weight loss. In one study, 50 overweight girls were instructed to drink about 16 ounces of water three times a day for eight weeks. By the end of the study, the girls not only lost weight, they also had a better body mass index (BMI) and improved body composition. (30) Similar findings were reported in adult women who increased their water intake while dieting. (26)
The amount of water you drink can also affect your cognitive abilities. Even mild dehydration can have a negative impact on your mood and cognition. (22)(24) Specifically, insufficient water intake can have detrimental effects on concentration, alertness, short-term memory, math skills, perception, and psychomotor skills. (2)
How much water do you need?
It used to be said that adults needed to drink eight 8-ounce glasses of water per day. However, new research highlights that determining your water requirements is not quite that simple. Gender, climate, and activity levels all play a role in determining how much water you need daily.
The National Academies of Science, Engineering, and Medicine provide the latest recommendations based on gender. According to their report, men should be consuming approximately 125 ounces every day and women should be consuming 91 ounces. (28) The report also notes that if you live in a hot climate or are very physically active, you will likely need to increase your intake. While these recommendations may seem excessive, keep in mind that these amounts include water intake from all sources, including foods.
An easy way to see if you’re drinking enough water is to check the color of your urine. If it is clear or a pale yellow color, you’re likely well-hydrated. Bright or dark yellow urine, however, indicates dehydration, so it’s time to drink up!
Did you know? By the time you realize you’re thirsty, you’re already dehydrated. (1)
The best type of water to drink
Choosing your water used to be as simple as turning on the tap. Today, bottled water is a $169.8 billion dollar market, and there is now a wide variety of waters from which to choose. (17) Below, we’ve summarized some of the many types of water available.
Tap water in most of North America is safe to drink. In the United States, the Environmental Protection Agency (EPA) sets standards and regulations for the presence of over 90 different contaminants in public drinking water, including E. coli, Salmonella, Cryptosporidium, metals such as lead, and some disinfectants. (10) Many individuals will utilize a water filter that not only removes any residual contaminants but also improves taste. (8)
Manufacturers of bottled spring water claim that it is bottled at the source—either a spring or glacier. Ideally, it should mean it contains relatively few contaminants. However, laboratory testing by the Environmental Working Group found that many popular brands of bottled water contain disinfectant byproducts, industrial chemicals, pharmaceutical drugs, and bacteria. (11)
Distilled water is produced by boiling water then collecting and condensing the steam. While this may be beneficial in areas where the local water may be contaminated, distilled water doesn’t contain the beneficial minerals found in tap water and some other types of water. (5)
Popular with some athletes, electrolyte water contains sodium, potassium, calcium, and magnesium—minerals often lost when you sweat. (27) This type of water may be beneficial if you live in a hot climate, suffer from an illness that enhances dehydration (like vomiting or diarrhea), or work out intensely for an hour or more.
Alkaline water has a higher pH than tap water as a result of the inclusion of alkaline minerals. It must also have negative oxidation reduction potential (ORP), the ability of water to act as a pro-oxidant or an antioxidant. The lower the ORP value, the more antioxidizing it is. While there is some preliminary animal research linking alkaline water to greater longevity, there is currently little research examining the health benefits of drinking alkaline water in humans. (15)
Rich in minerals such as sulfur, magnesium, and calcium, mineral water is sourced from underground mineral springs. Studies suggest that drinking mineral water may lower blood pressure in people with low magnesium and calcium levels. (25) Other research reports that drinking mineral water may also contribute to healthy bones. (9)(21)
Sparkling water is a popular choice among many people looking to increase their water consumption. While many sparkling waters are created by simply infusing tap water with carbon dioxide gas under pressure, natural sparkling water may contain minerals such as calcium, magnesium, potassium, silicon, and strontium. (14)(23) Most sparkling waters on the market will list the source of its bubbles either on the label or on their website.
Tips to increase your water intake
Eating foods with a high water content can help you meet your daily requirements. These include:
- Summer squash
- Watermelon (22)
Along with eating more water-rich foods, try these tips to help increase your daily water intake:
- Carry a water bottle with you wherever you go.
- Add sliced fruit or cucumbers to your water to enhance the flavor.
- Download a hydration app to help you remember to drink more water.
The bottom line
Staying hydrated is critical to good health. Whether you’re a fan of tap water, mineral water, or the sparkling variety, it’s important to consume the recommended amount of water every day. Not only will it keep your thirst at bay, it will help maintain key physiological functions that can improve your overall health and well-being.
- Adams WM, Vandermark LW, Belval LN, et al. (2019). The utility of thirst as a measure of hydration status following exercise-induced dehydration. Nutrients, 11(11), 2689.
- Adan, A. (2012). Cognitive performance and dehydration. Journal of the American College of Nutrition, 31(2), 71-78.
- Anti M, Pignataro G, Armuzzi A, et al. (1998). Water supplementation enhances the effect of high-fiber diet on stool frequency and laxative consumption in adult patients with functional constipation. Hepatogastroenterology, 45(21), 727-732.
- Arnaud MJ. (2003). Mild dehydration: a risk factor for constipation? European Journal of Clinical Nutrition, 57, S88-S95.
- Azoulay, A., Garzon, P., & Eisenberg, M.J. (2001). Comparison of the mineral content of tap water and bottled water. Journal of General Internal Medicine, 16(3), 168-175.
- Boilesen SN, Tahan S, Dias FC, et al. (2017). Water and fluid intake in the prevention and treatment of functional constipation in children and adolescents: is there evidence? Jornal de Pediatria, 93(4), 320-327.
- Boschmann M, Steiniger J, Hille U, et al. (2003). Water-induced thermogenesis. The Journal of Clinical Endocrinology & Metabolism, 88(12), 6015-6019.
- Brown, K.W., Gessesse, B., Butler, L.J., & MacIntosh, D.L. (2017). Potential effectiveness of point-of-use filtration to address risks to drinking water in the United States. Environmental Health Insights, 11, 1178630217746997.
- Burckhardt P. (2008). The effect of the alkali load of mineral water on bone metabolism: interventional studies. The Journal of Nutrition, 138(2), 435S-437S.
- Centers for Disease Control and Prevention. (2009). Water quality and testing. https://www.cdc.gov/healthywater/drinking/public/water_quality.html
- Environmental Working Group. (2019). Top 5 reasons to choose filters over bottled water. EWG’s Tap Water Database – 2019 Update. https://www.ewg.org/tapwater/bottled-water-resources.php
- García-Arroyo FE, Christóbal M, Arellano-Buendia AS, et al. (2016). Rehydration with soft drink-like beverages exacerbates dehydration and worsens dehydration-associated renal injury. American Journal of Physiology. Regulatory, integrative and comparative physiology, 311(1), R57-R65.
- Irwin C, Leveritt M, Shum D, et al. (2013). The effects of dehydration, moderate alcohol consumptions, and rehydration on cognitive functions. Alcohol, 47(3), 203-213.
- Liger-Belair, G., Sterenberg, F., Brunner, S., Robillard, B., & Cilindre, C. (2015). Bubble dynamics in various commercial sparkling bottled waters. Journal of Food Engineering, 163, 60-70.
- Magro, M., Corain, L., Ferro, S., Baratella, D., Bonaluto, E., Terzo, M., Corraducci, V., … Vianello, F. (2016). Alkaline water and longevity: a murine study. Evidence Based Complementary and Alternative Medicine, 2016, 3084126.
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- Murray B. (2007). Hydration and physical performance. Journal of the American College of Nutrition, 26(5), 542S-548S.
- Naghii MR. (2000). The significance of water in sport and weight control. Nutrition and Health, 14(2), 127-132.
- National Research Council (US) Committee on Diet and Health. (1989). Diet and Health: Implications for Reducing Chronic Disease Risk. Washington (DC), National Academics Press. Water-soluble vitamins. https://www.ncbi.nlm.nih.gov/books/NBK218756/
- Orchard TS, Larson JC, Alghotani N, et al. (2014). Magnesium intake, bone mineral density, and fractures: results from the Women’s Health Initiative Observational Study. American Journal of Clinical Nutrition, 99(4), 926-933.
- Popkin BM, D’Anci KE, & Rosenberg IH. (2010). Water, hydration and health. Nutrition Review, 68(8), 439-458.
- Quattrini, S., Pampaloni, b., & Brandi M.L. (2016). Natural mineral waters: chemical characteristics and health effects. Clinical Cases in Mineral and Bone Metabolism, 13(3), 173-180.
- Riebl SK & Davy BM. (2013). The hydration equation: update on water balance and cognitive performance. ACSMs Health & Fitness Journal, 17(6), 21-28.
- Rylander R & Arnaud MJ. (2004). Mineral water intake reduces blood pressure among subjects with low urinary magnesium and calcium levels. BMC Public Health, 4, 56.
- Stookey JD, Constant F, Popkin BM, et al. (2008). Drinking water is associated with weight loss in overweight dieting women independent of diet and activity. Obesity, 16(11), 2481-2488.
- Tang, Y., Want, D., Li, J., Li, X., Wang, Q., Liu, N., Liu, W., & Li, Y. (2016). Relationships between micronutrient losses in sweat and blood pressure among heat-exposed steelworkers. Industrial Health, 54(3), 215-223.
- The National Academies of Sciences, Engineering, and Medicine. (2004). Report sets dietary intake levels of water, salt, and potassium to maintain health and reduce chronic disease risk. https://www.nationalacademies.org/news/2004/02/report-sets-dietary-intake-levels-for-water-salt-and-potassium-to-maintain-health-and-reduce-chronic-disease-risk
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