📅 December 13, 2025 • 11 min read • Hydration

Hydration Myths: How Much Water Do You Really Need?

Is 8 glasses a day really necessary? Discover the truth about hydration, water needs, and common myths. Learn how to optimize your fluid intake for health and performance.

Common Hydration Myths

  • Myth: You must drink 8 glasses a day.
    Fact: Needs vary by person, activity, and climate.
  • Myth: Thirst means you’re already dehydrated.
    Fact: Thirst is a normal signal to drink, not a sign of danger.
  • Myth: Coffee and tea dehydrate you.
    Fact: Caffeine has a mild effect, but these drinks still count toward hydration.
  • Myth: Clear urine means perfect hydration.
    Fact: Light yellow is normal and healthy.

How Much Water Do You Need?

General guideline: 30–35 ml per kg body weight per day. For a 70 kg person, that’s about 2.1–2.5 liters. Needs increase with heat, exercise, and illness.

Body Weight (kg) Recommended Water (L/day)
50 1.5–1.8
70 2.1–2.5
90 2.7–3.2

Factors Affecting Water Needs

  • Physical activity
  • Hot or humid weather
  • Illness, fever, or vomiting
  • Pregnancy or breastfeeding
  • High-protein or high-fiber diet

Signs of Dehydration

  • Dark yellow urine
  • Dry mouth or lips
  • Headache or dizziness
  • Fatigue
  • Confusion (in severe cases)

Tips for Staying Hydrated

  • Drink regularly throughout the day
  • Carry a water bottle
  • Eat water-rich foods (fruits, vegetables, soups)
  • Listen to your thirst
  • Increase intake in heat or during exercise

Key Takeaway

Hydration needs sú individuálne. Počúvaj svoje telo, sleduj moč a prispôsob príjem podľa aktivity a prostredia.