How Much Do You Need?
The NHMRC recommends approximately 2.6 L/day for adult men and 2.1 L/day for adult women as adequate intakes from all sources (beverages and food). In hot climates — common across much of Australia — or during exercise, these requirements increase.
Practical Hydration Checks
Urine colour is a simple, though imperfect, indicator. Pale straw generally suggests adequate hydration. Dark amber may indicate a need for more fluid. Other signs of mild dehydration include fatigue, headache, reduced concentration and dry mouth.
Hydration Around Exercise
| Timing | Recommendation | Why |
|---|---|---|
| 2–3 hours before | 400–600 mL water | Allows absorption; excess excreted before session |
| During (<60 min) | 150–250 mL every 15–20 min | Water alone usually sufficient |
| During (>60 min) | As above + electrolytes | Sodium supports fluid retention |
| Post-exercise | 1.25–1.5 L per kg lost | Accounts for ongoing sweat losses |
Electrolytes
Sodium, potassium, magnesium and calcium are lost through sweat. For most people, a balanced diet covers daily electrolyte needs. During prolonged exercise in heat, a simple homemade rehydration drink — 500 mL water, ¼ tsp salt, squeeze of citrus — provides adequate sodium without the sugar content of many commercial sports drinks.
Caffeine & Fluid Balance
Moderate coffee and tea consumption (3–4 cups/day) contributes to daily fluid intake. While caffeine has a mild diuretic effect, habitual consumers develop tolerance, and net fluid loss is minimal. Both tea and coffee count toward your daily total.
Hot Weather Considerations
Australia's summers can be extreme. Outdoor workers, athletes training in heat, and those spending extended time in the sun should proactively increase fluid intake. Heat acclimatisation — gradually increasing exposure over 10–14 days — improves the body's thermoregulatory efficiency and sweat response.