Sweat and salt (Read 413 times)

Does anyone know what the approximate loss of potassium and salt is in each lb of sweat? Also, does anyone know why sweating more is associated with a higher potential for iron and hemoglobin deficiencies? What exactly is in sweat that would make our iron levels go down?

Potassium - very little if any at all potassium is contained in sweat.

Sodium - highly variable.  Sweat contains between 2.2 - 3.4 grams of salt per liter. A liter of sweat weighs 2.2 lbs. So, for every pound of sweat that you loose, you put out 1-1.5 grams of salt. In the Summer heat, most folks sweat a pound during every mile or two of running.

Iron - no, this does not happen, why do you think sweating causes iron to drop?

It is true that runners can get low iron.  The cause for this is not known and likely has little to do with sweating iron, but who knows.  Others have suggested that pounding breaks up red blood cells as they travel through the feet's capillaries.  But who knows.

Salt content does vary per person and within people over the course of their lives and each season.  Loads of things influence this, including adaptation and genetics and, maybe, weight.