6 Evidence-Based Health Benefits of Drinking Enough Water

Person pouring water into a glass

Getty Images / Thomas Barwick

Hydration is vital to health, no matter what level of physical exertion you participate in during the day. Ensuring you keep hydrated amidst different activities—whether taking care of your kids, finishing the workday, or running a marathon—is necessary for safety and performance.

Water is abundant in the human body, with 60 to 70% of body weight coming from water. Every system and metabolic activity in your body depends on water to operate. For the most part, water intake and output are dynamically balanced. Sometimes, your water intake needs to increase or decrease; finding that balance and drinking the optimal amount can provide several benefits.

There are several reasons to drink water for your health, including improved skin, digestion, weight management, performance, and more.

Everyone's hydration needs are unique and constantly in flux, so listening to your body is best. However, there are some basic guidelines you can turn to for more direction and information for more complex concerns around exercise hydration needs. See the International Society of Sport's Nutrition or American College of Sports Medicine position on hydration.

Helps With Weight Balance

Drinking water can help you achieve and maintain a healthy weight balance. Although there are many health metrics aside from weight, maintaining an ideal weight range for your height and body frame will reduce your risks of many diseases, including heart disease, type 2 diabetes, and metabolic dysfunction.

Hydrating optimally can support fat loss through increased lipolysis (fat burning). Research shows that mild, but consistent, under-hydration is associated with increased body weight.

While the myth that when you believe you're hungry, you really might be thirsty is not supported by science and can lead to disordered thoughts around eating, drinking plenty of water can indeed help you feel more energized and full, avoiding cravings for salt or energizing calorie-dense quick snacks that may not be nutritious.

Supports Healthy Skin

Drinking water can boost the hydration of your skin, helping prevent dryness and signs of aging. Hydrated skin helps provide a barrier and prevents several skin conditions like dryness and roughness.

Studies show that the effect of drinking more water has on your skin's hydration level depends on your current habits. If you already get sufficient water, you likely won't see noticeable benefits, but if you are chronically under-hydrated, you likely will see improvement and less dry, irritated skin.

Increases Aerobic Capacity

According to the International Society of Sports Nutrition, the most important nutritional performance-enhancing aid for athletes is water, and avoiding dehydration while active helps ensure exercise capacity. Before you start working out, it is highly recommended to ensure you've hydrated adequately.

Research shows that proper hydration can help you work out longer and at higher intensities. Dehydration can impair your performance, with laboratory data showing a 2% body weight loss from fluid loss, reducing aerobic efficiency.

Avoid Overhydration

It's important to note that you should only drink enough to satisfy hydration needs and not over-hydrate. If you consume too much water, your stomach will become distended. Blood flow diverts from your working muscles to your digestive system to facilitate the excess water and elimination needs. Over-hydration can become dangerous; it's something to be aware of as you work to meet your hydration needs.

Enhances Power and Strength

Ensuring adequate hydration is vital for any athlete's aerobic capacity, anaerobic power and capacity, muscular endurance and power, strength, and focus. Experts agree on following your body's cues when it comes to drinking before, during, and after exercise. Over-hydration can cause just as many issues for performance.

Experts suggest following voluntary hydration needs by keeping water within reach, but not drinking more than you naturally feel inclined to.

Boosts Cognition

Cognition is also affected by losing 2% body mass from fluids. The effects are seen as a loss of short-term memory and impairment of tasks that require psychological and physical tracking. All bodily functions require water, and the brain depends on proper hydration to function fully.

Research suggests that adults, including older adults, and children, tend not to drink enough water, increasing dehydration risk and associated side effects. Studies on children reveal that even with mild dehydration, drinking 300 to 1000 mL of water improves cognitive performance.

Improves Digestion

Proper hydration aids with the digestion of food and helps you absorb nutrients from the digestive tract. Nutrients in your digestive tract need to dissolve to be readily absorbed into the bloodstream and water is crucial for this process to occur.

As well, if you aren't properly hydrated, digestion will slow, which can lead to constipation. In fact, a lack of drinking water or other liquids is considered a primary contributor to chronic constipation.

A Word From Verywell

Water is vital for health and is required for countless bodily functions. This means that everything from your brain health and mood to your digestion and athletic performance is affected by your hydration levels. Ensure you drink enough water without going overboard by listening to your body's needs and keeping water within reach throughout the day. If you are concerned about dehydration or your specific needs, consult a health care provider.

Frequently Asked Questions

  • What are symptoms of dehydration?

    Symptoms of dehydration include headache, confusion, fatigue, lightheadedness, dry mouth, muscle cramps, swollen feet, dry cough, high heart rate, and more.

  • How long does it take to see the benefits of drinking water?

    This largely depends on how dehydrated you are to begin with. The more balanced you are in your water consumption, the easier it is for your body to "catch up" when you replenish that water supply.

11 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Zhang J, Zhang N, He H, Du S, Ma G. Different amounts of water supplementation improved cognitive performance and mood among young adults after 12 h water restriction in Baoding, china: a randomized controlled trial(Rct). IJERPH. 2020;17(21):7792. doi:10.3390%2Fijerph17217792

  2. Daniels MC, Popkin BM. Impact of water intake on energy intake and weight status: a systematic reviewNutr Rev. 2010;68(9):505-521. doi:10.1111/j.1753-4887.2010.00311.x

  3. Kerksick CM, Wilborn CD, Roberts MD, et al. ISSN exercise & sports nutrition review update: research & recommendations. Journal of the International Society of Sports Nutrition. 2018;15(1):38. doi:10.1186/s12970-018-0242-y

  4. Thornton SN. Increased hydration can be associated with weight loss. Front Nutr. 2016;3. doi:10.3389%2Ffnut.2016.00018

  5. Akdeniz M, Tomova-Simitchieva T, Dobos G, Blume-Peytavi U, Kottner J. Does dietary fluid intake affect skin hydration in healthy humans? A systematic literature review. Skin Res Technol. 2018 Aug;24(3):459-465. doi: 10.1111/srt.12454

  6. Rodrigues L, Palma L, Tavares Marques L, Bujan Varela J. Dietary water affects human skin hydration and biomechanics. CCID. Published online August 2015:413. doi:10.2147%2FCCID.S86822

  7. Backes TP, Fitzgerald K. Fluid consumption, exercise, and cognitive performanceBiol Sport. 2016;33(3):291-296. doi:10.5604/20831862.1208485

  8. Savoie FA, Kenefick RW, Ely BR, Cheuvront SN, Goulet EDB. Effect of hypohydration on muscle endurance, strength, anaerobic power and capacity and vertical jumping ability: a meta-analysis. Sports Med. 2015;45(8):1207-1227. doi:10.1007/s40279-015-0349-0

  9. Drozdowska A, Falkenstein M, Jendrusch G, et al. Water consumption during a school day and children’s short-term cognitive performance: the cognidrop randomized intervention trial. Nutrients. 2020;12(5):1297. doi:10.3390/nu12051297

  10. European Hydration Institute. Hydration.

  11. Forootan M, Bagheri N, Darvishi M. Chronic constipation: A review of literature. Medicine. 2018;97(20):e10631. doi: 10.1097/MD.0000000000010631

Additional Reading

By Rachel MacPherson, BA, CPT
Rachel MacPherson is a health writer, certified personal trainer, and exercise nutrition coach based in Montreal.