When you exercise, your body naturally sweats in order to cool itself off. The sweat has a definite amount of salt in it, which is why your sweat tastes salty. Also, The more you sweat, the more salt that leaves your body.
Aldosterone and antidiuretic hormone help control sodium and water balance in the body. Aldosterone, secreted by the kidneys, increases the reabsorption of water and sodium. Antidiuretic hormone reduces the amount ofwater excreted in the urine.
