Rawstone Learn
Plain-English guides to sodium, electrolytes and hydration. No jargon, no medical claims, just the physiology explained the way we wish someone had explained it to us. General education, not medical advice.
Lose 2% of your body weight in water and focus, mood and reaction time drop. What the studies show, why it happens, and why thirst comes late.
Reading labelsFive checks, about a minute: sodium per serve, sugar, the sweetener grade, the magnesium form, and whether each batch is lab tested.
The ScienceWhy the concentration of sodium in your glass matters more than the milligrams printed on the pack.
SodiumThe calm, plain-English context behind a number that looks big at first glance, and how to start with half.
MineralsTwo common forms, two very different results in a glass of water. The simple chemistry behind the label, with the maths shown.
TasteWhy some stevia tastes bitter and some doesn't, and how to tell which one is in your tub.
FastingThe minerals carry no energy, so the honest answer comes down to the carbs and sugars per serve.
KetoWhy cutting carbs flushes more salt through your kidneys, and what the flat, foggy keto-flu feeling often comes down to.
Put in how long you trained and how hard you sweated, and get a rough idea of how much sodium left your body and roughly how many serves that is worth putting back. There is a printable one-page cheat sheet too.
Open the sweat calculator → Get the cheat sheet