Hydration before, during, and after
The single most important habit for safe and effective sauna use — exact volumes for each phase, plus signs of dehydration.
Sauna sessions cause significant fluid loss through sweat. Hydration is the single most important habit for safe and effective use.
Before
- 16 oz / 500 ml of water 15 minutes before the session
- Avoid alcohol completely (see Section 14.2)
During
- Sip water as you feel thirsty
- A 16 oz / 500 ml bottle inside the sauna for a 20-minute session is reasonable
- For longer sessions or in hot climates, consider electrolyte drinks instead of plain water
After
- 16 oz / 500 ml of water within 15 minutes of stepping out
- Continue drinking water in the hour after
- If you sweated heavily, electrolytes (in water or a salty snack) help replace what you lost
Signs of dehydration
- Headache
- Fatigue
- Dark urine
- Dizziness or lightheadedness
If you experience these during or after a session, drink water and rest before the next session.