I sweat like a horse and I've had people comment on the relatively high amount of salt crust I end up covered in (face, clothes, etc....my cats love when I walk in the door like a human salt lick after a ride or run). I pop Endurolytes like candy on long, hot weather rides. I'm super prone to cramping and gave up on Marathons, as a result. I just couldn't get enough fluids or electrolytes in while running for that length of time.