Stress Pak Electrolytes are literally the spark of life at the cellular level. In the body, electrolyte ions are passing in and out through each cell performing very important tasks. Some of the more important functions are: Moving electrical charges across cells, Nerve response,Electrical change in cells,and Balancing both ph and fluid levels. Stress-Pak contain the same mineral salts lost in your horses sweat. The horses body is constantly trying to balance the electrolytes in and outside of the cells.