For myself, taking SCaps during long periods of exercise in hot and/or windy conditions is a must. When i started doing 20+ mile runs i suffered 2 instances of mild hyponatremia. Very scary. Drinking alot of water w/o proper sodium intake can cause 'water intoxication'. Most recently i suffered on PikesPeak. I forgot the caps and suffered terribly. I'd never carried the caps up PikesPeak before but due to the extreme heat and excessive sweating i suffered w/o them. This is how i know it is not a placebo effect w/ me. Everyone is different though.