Hot Yoga Hydration Calculator
Estimate how much fluid to drink before, during and after a hot yoga class based on session length and sweat rate.
How it works
Sweat loss = sweat rate(mL/hr) × hours · Total = 500 mL pre + loss during + 0.5 × loss post
Hot yoga rooms (often 35–40°C) drive high sweat rates, so hydration should be planned around the session, not just topped up afterward. A practical framework is to arrive well-hydrated (about 500 mL a couple of hours before), sip steadily during class to offset losses, and replace the remainder afterward — aiming for roughly 125–150% of fluid lost because some is passed as urine. Weighing yourself before and after class is the most accurate way to personalise this.
Worked example
A 60-minute class at a heavy sweat rate of 1.5 L/hr loses about 1.5 L. Plan ≈500 mL beforehand, ≈1.5 L sipped during class, and ≈0.75 L after — roughly 2.75 L total, about 11 cups.
Frequently asked questions
How do I find my real sweat rate?
Weigh yourself (minimal clothing) right before and after class, and note any fluid you drank. Each kilogram lost is about 1 litre of sweat: sweat loss = weight lost + fluid drunk. Divide by class hours for your rate, then use that here.
Do I need electrolytes for hot yoga?
For a single class, water usually suffices if you eat normally. For very long, very sweaty sessions or back-to-back classes, adding sodium (and some potassium) helps you retain fluid and avoid the dilutional effects of drinking large volumes of plain water.
Can I drink too much?
Yes. Overdrinking far beyond your losses can dilute blood sodium (hyponatremia), which is dangerous. Match intake roughly to losses rather than forcing large volumes, and let thirst guide you during class.
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Educational estimate only, not medical advice. Recovery, hydration, heat and cold tolerance vary widely between individuals — stop any protocol that causes pain, dizziness or distress and consult a qualified professional.