Is the 8-glass rule accurate?
Oversimplified. Actual needs vary widely by weight, activity, climate. 8 glasses works for ~2kg person in moderate conditions but misses individual variation.
How much water for exercise?
Add 400-800 ml per hour of moderate activity. Intense efforts higher. Hydrate during and after exercise, not just before.
Does caffeine really increase hydration needs?
Mild diuretic effect; increases urine output slightly. Regular consumers develop tolerance. Net effect small but noticeable in calculator.
Can you drink too much water?
Hyponatremia (low blood sodium) rare but possible from extreme overconsumption. Drink to thirst; overhydration in endurance athletes mainly.
How does climate affect hydration?
Heat increases perspiration, raising losses 50-100%. Cold/dry climates also boost insensible losses. Calculator adjusts for both.
Is urine color a reliable hydration marker?
Generally yes. Pale straw = hydrated; dark amber/brown = dehydrated. Medications, supplements affect color; use as rough guide.
Should I drink before thirst?
During exercise yes; thirst lags actual need. In daily life, thirst is reliable. Exceptions: older adults, athletes, hot environments.
Does food water count toward daily intake?
Yes, ~20% of water comes from food (fruits, vegetables, soups). Contributes to daily requirement; beverages make up remainder.
Can electrolytes replace water alone?
For intense/long exercise yes; electrolytes (sodium, potassium) enhance absorption and retention. For daily hydration, plain water sufficient.
Is filtered/bottled water necessary?
Tap water meets safety standards in most developed countries. Bottled/filtered adds cost/waste without health benefit unless local supply contaminated.