How Much Water Do You Need?
The general formula: 30–40 ml per kg of body weight. A 70 kg adult needs 2.1–2.8 litres daily. Active individuals and those in hot climates need more.
Factors That Increase Water Needs
- Exercise: Add 500–1000 ml per hour of activity
- Hot weather: Add 500+ ml on hot/humid days
- Altitude: Higher altitude increases water loss
- Pregnancy/breastfeeding: Add 300–700 ml daily
- Illness: Fever, diarrhea, vomiting increase fluid needs
Signs of Dehydration
- Dark yellow urine (aim for pale straw colour)
- Headaches and dizziness
- Dry mouth and skin
- Fatigue and difficulty concentrating
- Reduced urine output
Best Times to Drink Water
Morning (kickstarts metabolism), 30 min before meals (aids digestion), before/during/after exercise, and when feeling hungry (thirst is often mistaken for hunger).
Water Intake Myths Debunked
The "8 glasses a day" rule has no scientific origin — individual needs vary. Coffee and tea do count toward hydration (the diuretic effect is minimal). Overhydration (hyponatremia) is rare but possible in extreme endurance activities.