top of page

General Health and Wellness 

The Importance of Hydration:
How It Affects Health, Work, and Sports

Think of your body like a high-performance engine: even a small drop in coolant can make it sputter. The same goes for us with water. Losing just 2 pounds of fluid in a 150-lb person—basically the weight of a big water bottle—can make you feel sluggish, overheated, and far from your best.

 

The good news? A glass of water is often the cheapest, fastest “performance enhancer” out there.

Why Hydration Matters:

About 60% of your body is water—so in a way, you’re more “liquid” than “solid.” Water keeps blood moving, food digesting, temperature steady, and nutrients on delivery duty (Popkin et al., 2010). When you stay hydrated:

  • Your body performs better:

    • Muscles contract like well-oiled machines, you regulate heat more easily, and you bounce back faster.

  • Your brain works sharper:

    • Hydration boosts focus, memory, and mood (Masento et al., 2014). In other words, water can make you less grumpy and more productive.

  • Your health stays protected:

    • Proper hydration helps prevent kidney stones, constipation, and energy crashes (Armstrong & Johnson, 2018).

Effects of Dehydration:

It doesn’t take much water loss to knock you off your game:

  • A 150-lb (68 kg) woman losing 1.5–3 lbs of fluid (1–2%) can feel drained.

  • A 180-lb (82 kg) man losing 1.8–3.6 lbs of fluid is already in the “slow down” zone.

 

This small dip can cause:

  • Physical drag: Less endurance, more fatigue, weaker muscles, and higher risk of overheating (Cheuvront & Kenefick, 2014).

  • Mental fog: Slower reaction times, poor focus, and irritability (Adan, 2012).

  • Serious risks: If it continues, heat stroke and kidney problems can follow (Kleiner, 1999).

 

Fun fact: Astronauts in space carefully monitor hydration, because even mild dehydration makes them dizzy and confused—which is not great when flying a spaceship.

Signs of Dehydration (and Proper Hydration):

Here’s the catch: by the time you feel thirsty or notice dark urine, you’re already late to the hydration party (Armstrong, 2007).

 

Earlier signs to watch for:

  • Headache or that “brain fog” feeling

  • Feeling more tired than usual

  • Dry lips or skin

  • Less sweat than normal during activity

  • A slightly racing heartbeat or feeling warmer than usual

 

Later signs:

  • Strong thirst

  • Dark yellow urine

  • Dizziness or lightheadedness

  • Muscle cramps

 

Signs you’re doing well:

  • Pale yellow urine (think “lemonade,” not “apple juice”)

  • Energy that stays steady

  • You don’t constantly crave water

General Guidelines for Staying Hydrated:

There’s no one-size-fits-all, but these guidelines work for most people:

  • Daily needs: Women ~2.7 L/day; Men ~3.7 L/day (includes food + drinks) (National Academies of Sciences, 2019).

  • Before activity: Drink ~500 mL (17 oz) about 2–3 hours before (Sawka et al., 2007).

  • During activity: Sip every 15–20 minutes—more if it’s hot or sweaty.

  • After activity: Drink 1.25–1.5 L for every 1 kg body weight lost. (Yes, this is why athletes sometimes weigh themselves before and after workouts!)

​​

Caffeine:

Two to three cups of coffee or a few teas a day won’t dry you out (Maughan & Griffin, 2003). Still, it’s smart to add an extra cup (240 mL) of water for every caffeinated drink.

 

Alcohol:

Sorry, your beer doesn’t count as hydration. Alcohol makes you lose fluids faster. Rule of thumb: one glass of water for every alcoholic drink. Your tomorrow-morning self will thank you.

Screenshot 2025-08-27 at 4.50.06 PM.png

What Increases the Risk of Dehydration:

Certain situations make it easier to dry out:

  • Exercise + heat: Sweat is basically your body’s built-in sprinkler system, but it drains fluids quickly.

  • Illness: Fever, vomiting, diarrhea = water loss on overdrive.

  • High altitude: Faster breathing means faster fluid loss (Beis et al., 2012).

  • Age:

    • Older adults: Thirst mechanism weakens (Hooper et al., 2015).

    • Kids: Smaller bodies lose water quicker (Kavouras, 2002).

  • Lifestyle: Lots of alcohol, excess caffeine without extra water, or forgetting to drink during busy days.

  • Work & sport: Construction workers, farmers, and athletes in the heat are on the front lines (Carter et al., 2005; Kenefick & Sawka, 2007).

Key Takeaway:

Hydration isn’t just about sipping water when you’re thirsty—that’s already late. Watch for early signs like fatigue or headache, pair every coffee or cocktail with water, and be extra mindful in hot weather, during illness, or if you’re young, older, or active. A simple bottle of water can be the cheapest upgrade to your health, focus, and performance.

Scientific References:

  • Adan, A. (2012). Cognitive performance and dehydration. Journal of the American College of Nutrition, 31(2), 71–78.

  • Armstrong, L. E. (2007). Assessing hydration status: The elusive gold standard. Journal of the American College of Nutrition, 26(5), 575S–584S.

  • Armstrong, L. E., & Johnson, E. C. (2018). Water intake, water balance, and the elusive daily water requirement. Nutrients, 10(12), 1928.

  • Beis, L. Y., Wright-Whyte, M., Fudge, B., Noakes, T., & Pitsiladis, Y. P. (2012). Drinking behaviors of elite male runners during marathon competition. Clinical Journal of Sport Medicine, 22(3), 254–261.

  • Carter, R., Cheuvront, S. N., & Sawka, M. N. (2005). Fluid replacement and heat stress. Journal of Sports Sciences, 23(7), 709–718.

  • Cheuvront, S. N., & Kenefick, R. W. (2014). Dehydration: Physiology, assessment, and performance effects. Comprehensive Physiology, 4(1), 257–285.

  • Hooper, L., Bunn, D., Jimoh, F. O., & Fairweather-Tait, S. J. (2015). Water-loss (intracellular) dehydration assessed with serum osmolality and risk of mortality in older people. Journal of Gerontology: Series A, 70(10), 1223–1229.

  • Kavouras, S. A. (2002). Assessing hydration status. Current Opinion in Clinical Nutrition and Metabolic Care, 5(5), 519–524.

  • Kenefick, R. W., & Sawka, M. N. (2007). Hydration at the work site. Journal of the American College of Nutrition, 26(5), 597S–603S.

  • Kleiner, S. M. (1999). Water: An essential but overlooked nutrient. Journal of the American Dietetic Association, 99(2), 200–206.

  • Masento, N. A., Golightly, M., Field, D. T., Butler, L. T., & van Reekum, C. M. (2014). Effects of hydration status on cognitive performance and mood. British Journal of Nutrition, 111(10), 1841–1852.

  • Maughan, R. J., & Griffin, J. (2003). Caffeine ingestion and fluid balance: A review. Journal of Human Nutrition and Dietetics, 16(6), 411–420.

  • National Academies of Sciences, Engineering, and Medicine. (2019). Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press.

  • Popkin, B. M., D’Anci, K. E., & Rosenberg, I. H. (2010). Water, hydration, and health. Nutrition Reviews, 68(8), 439–458.

  • Sawka, M. N., Burke, L. M., Eichner, E. R., Maughan, R. J., Montain, S. J., & Stachenfeld, N. S. (2007). American College of Sports Medicine position stand: Exercise and fluid replacement. Medicine & Science in Sports & Exercise, 39(2), 377–390.

bottom of page