It's true that it varies. It would also depend on the temperature, how much fluid you've had to drink (or through IV if you day doesn't end so well!), etc.

On some very long and energetic bike rides on a hot day, I have found myself mildly nauseous and craving salt. Usually a pinch does the trick. Very salty food (hmmmm... poutine! or a hot dog!) also instantly makes me feel better, but I'm afraid it's overkill.