Daily Water Intake

Yes — caffeinated drinks do contribute to hydration despite being mild diuretics. The net effect of tea and coffee is still hydrating for most people at normal consumption levels. Alcohol, however, causes net fluid loss and should not be counted.

The simplest indicator is urine colour. Pale yellow indicates good hydration. Dark yellow or amber suggests you need more water. Clear urine may indicate overhydration. Thirst is a reliable signal in healthy adults, though older adults may have a diminished thirst response.

Yes significantly. Sweating during exercise or in heat can increase fluid losses to 1–2 litres per hour. Sports guidelines recommend drinking 500 mL of water 2 hours before exercise, sipping regularly during exercise, and rehydrating after based on weight lost during the session.