Heat · Sweat · Hydrate · Recover

What to Drink Before a Sauna Session

Most of the hydration talk around sauna is about what to do afterwards. But how you feel in the heat, and how quickly you bounce back, starts before you open the door. This is the "before" deep dive from our sauna recovery guide: what to drink, when to drink it, and what to leave for later.

Electrolyte drink and towel beside a sauna door
Good recovery starts before you open the door.

The Short Answer

Before a sauna, drink water with some sodium over the 1–2 hours beforehand, then take a few small sips 15–30 minutes before you go in. Pre-loading electrolytes helps your body hold on to that fluid. Skip alcohol, keep caffeine and sugary drinks light, and avoid gulping a big volume right before the session.

Why Pre-Sauna Hydration Matters

Starting the session already low

Plenty of us walk into the sauna slightly behind on fluid: after a morning coffee, a workout, a flight, or a long day where water got forgotten. Heat then asks for more. Starting low means you reach the point of feeling flat, light-headed or headachy sooner, and recovery takes longer afterwards.

The aim isn't to flood your system. It's to arrive comfortably hydrated, with enough sodium on board that your body keeps the fluid instead of passing it straight through.

Sweat losses in a typical session

Traditional saunas usually run at around 80–100°C, and a typical session can see you sweat around half a litre (Hannuksela & Ellahham, 2001). Sodium is the main mineral that goes with it, and how much varies a lot between people (Baker, 2017). We cover the numbers in how much sodium you lose in a sauna.

When to Drink: A Simple Timeline

Pre-sauna hydration timeline

1–2 hours before

This is your main window. Drink a glass or two of fluid with some sodium in it, and have a light snack if you haven't eaten. Sports medicine guidance for exercise suggests drinking ahead of time so your body has a few hours to absorb what it needs and pass any excess (ACSM, 2007). The same logic works well for heat sessions.

15–30 minutes before

Keep it to a few easy sips. Use the bathroom. Get your bottle ready for afterwards so rehydrating is the first thing you do when you step out.

What to Drink

Water and why it isn't the whole story

Water is the foundation, and on light days it may be all you need. But water on its own, especially in large amounts, tends to move through quickly. Adding sodium changes how much of it your body keeps. We explain the difference in more depth in water vs electrolytes after sauna, and the same principle applies before.

Pre-loading electrolytes (sodium first)

Pre-loading simply means having electrolytes before you sweat instead of only afterwards. It's built on the same idea as oral rehydration: sodium helps your body absorb and hold on to fluid. If you're curious about the science, see what is ORS hydration?

Sodium is the one to prioritise, because it's the mineral you lose most in sweat. That's why we wrote a whole piece on why high sodium electrolytes matter.

A pre-sauna glass of Saunabodi Electrolytes gives you 700mg sodium, with 250mg potassium and 60mg magnesium, and it has no added sugar, so it won't sit heavy before you go into the heat. Mix one stick into water an hour or so before your session.

Drinks to keep light: coffee, juice, sugary sports drinks

  • Coffee and tea: a normal cup is fine for most people. Research suggests moderate coffee intake doesn't dehydrate habitual drinkers (Killer et al., 2014). But caffeine raises heart rate, and so does heat, so keep it moderate and not right before you go in.
  • Juice: fine in small amounts, but it's mostly sugar and low in sodium.
  • Sugary sports drinks: designed to fuel long exercise. They're usually light on sodium relative to what you'll sweat out, and a big sugary drink can feel heavy in the heat.

What to Avoid

Alcohol

Skip it before and during sauna. Alcohol adds to fluid loss, affects blood pressure and judgement, and is one of the most consistent risk factors linked to sauna incidents in the research (Hannuksela & Ellahham, 2001). Save any celebrating for well after you've cooled down and rehydrated.

Very large volumes right before you go in

Downing a full bottle at the door doesn't give your body time to absorb it, and sitting in the heat feeling sloshy is no fun. Spread your fluids across the hour or two beforehand instead.

A Simple Pre-Sauna Routine

Pre-sauna drinks and snack laid out on a bench
  • Drink: one or two glasses of water over the 1–2 hours before.
  • Salt: add electrolytes or have something salty, especially on hot days or if you've trained.
  • Snack: something light, like a banana, toast or a handful of salted nuts. Don't go in hungry or overly full.
  • Skip: alcohol, and keep caffeine moderate.
  • Bottle ready: have your post-sauna drink waiting. Here's why you need electrolytes after sauna too.

Listen to your body. If you feel dizzy, confused, faint, have chest pain or start vomiting, stop, cool down and seek medical help. People with heart, kidney or blood pressure conditions, or who are pregnant, should check with their doctor before sauna use or adding extra sodium.

FAQ

What's the best drink before a sauna?

Water with some sodium, such as an electrolyte drink, taken over the 1–2 hours before your session. It helps you arrive hydrated and hold on to the fluid you drink.

How much water should I drink before a sauna?

There's no single number, but a glass or two in the hour or two before, plus a few sips just before, works for most people. Avoid drinking a large volume right at the door.

Should I take electrolytes before or after a sauna?

Both can help. Before helps you start with fluid and sodium on board; after replaces what you sweated out. On longer or hotter sessions, many people do both.

How long before a sauna should I hydrate?

Start 1–2 hours before so your body has time to absorb fluid, then take small sips 15–30 minutes before you go in.

Is it OK to drink coffee before a sauna?

A normal cup is fine for most people, as moderate coffee doesn't appear to dehydrate regular drinkers. Keep it moderate and not right before, since both caffeine and heat raise your heart rate.

Can I drink alcohol before a sauna?

It's best not to. Alcohol adds to fluid loss and affects blood pressure and judgement, and it's linked with sauna-related incidents. Save it for well after you've cooled down.

The Bottom Line

Pre-sauna hydration is simple: drink with a little sodium in the hour or two before, take a few sips just before, skip the alcohol, and have your recovery drink ready for afterwards. For the full picture, before, during and after, head to our sauna recovery guide.

Stay Hot. Stay Hydrated.

Shop SAUNABODI Electrolyte Mix

If you'd like an easy pre-sauna ritual, keep a stick of Saunabodi Electrolytes in your gym or spa bag. It's ORS-inspired, made with real fruit, with no artificial flavours, colours or sweeteners and no maltodextrin, and it's vegan, keto-friendly and gluten-, soy- and dairy-free. Try Pink Lemonade, Mixed Berry or Tropical Passion.

SAUNABODI Electrolyte Mix Mixed Berry box 30 stick packs Mixed Berry Made with real fruit, with no added sugar. Shop Mixed Berry → SAUNABODI Electrolyte Mix Tropical Passion box 30 stick packs Tropical Passion No artificial flavours, colours or sweeteners. Shop Tropical Passion → SAUNABODI Electrolyte Mix Pink Lemonade box 30 stick packs Pink Lemonade Vegan, keto-friendly, gluten-, soy- and dairy-free. Shop Pink Lemonade → SAUNABODI Electrolyte Mix Variety Box box 12 stick packs · try all three Variety Box Try all three flavours. Third-party tested. Shop Variety Box →

This article is general information, not medical advice. If you have a kidney, heart or blood pressure condition, or you are pregnant, check with your doctor before changing your sodium or electrolyte intake.

Sources

Keep reading

← Back to The Heat Code

Stay Hot. Stay Hydrated. We live in the heat.

Leave a comment