The Sauna Electrolyte Protocol

Sauna use is surging — the longevity research is real, the cardiovascular data is impressive, and the cold-plunge contrast is everywhere. What gets overlooked: a 20-minute sauna session can deplete more sodium than an hour of moderate running.

The Sweat Math

In a 180°F dry sauna, average sweat rates run 0.5–1 L per 20-minute session. Sodium concentration in sweat ranges from 400–1500 mg/L depending on individual physiology and acclimation. That's potentially 1–1.5 g of sodium lost in a single session.

Why Plain Water Backfires

Drinking 32 oz of plain water after a sauna session into an already-depleted electrolyte pool dilutes plasma sodium further. The classic post-sauna symptoms — light-headedness, headache, mid-night calf cramps — are usually electrolyte issues, not "toxins."

The Protocol

• Pre-sauna (30 min before): 500 mg sodium + 16 oz water
• Between rounds: 8 oz water with no added salt — you've already pre-loaded
• Post-sauna (within 30 min): 500–1000 mg sodium, 200–300 mg potassium, 100–200 mg magnesium with 16–24 oz water
• 1 hour later: Another 16 oz of plain water to complete rehydration

For Multi-Round Sessions

Three 20-minute rounds with cold plunges between is a common protocol. For heavy sweaters, add an extra 500 mg sodium dose between rounds 2 and 3.

Sauna Before vs After Training

A sauna after training adds to your daily sweat loss. Stack the post-training electrolyte dose with the post-sauna one — don't double-count, but don't skip either.

The Bottom Line

Treat a sauna session like a workout. Pre-load sodium, sip water in moderation, and replace what you lose afterwards. The "sauna headache" disappears fast when you do.