If you're sweating, you need to be salting. Even elite athletes can miss this connection. American 100-mile record holder and host of the Human Performance Outliers podcast @zachbitter learned the hard way: chugging plain water to catch up on hydration isn't enough. ⁠ ⁠ Drinking plain water ➡️ greater urine output ➡️ less water retained. ⁠ ⁠ With less blood volume, your heart has to beat faster to deliver the same amount of oxygen, and that blood gets split between feeding your working muscles and cooling your skin.⁠ ⁠ Once you lose ~2% of your body weight in sweat, that cost shows up on the clock (PMID: 17277604) and how you feel during and after your race.⁠ ⁠ The fix is pretty simple: add sodium.⁠ ⁠ Drinking fluids that contain sodium helps your body retain more of the fluid you drink. In one study, sodium-containing drinks restored 174% of the fluid people lost, compared with just 78% when they drank plain water. (PMID: 3403476)⁠ ⁠ Stay Salty ⚡