I've concluded that maybe my electrolytes get depleted on my five-hour rides. I wasn't convinced enough to spend the big bucks on Endurolyte capsules, but I figured I didn't have anything to lose by making my own.
I looked at the analysis for the Endurolytes,
and calculated that to make the equivalent, I would need:
.07 tsp Salt
.04 tsp Salt Substitute (KCl -- "No Salt" brand)
.15 tsp Calcium supplement powder
.25 tablet of Magnesium supplement (ground up, about .06 tsp)
So, roughly, I mix these powders up at a ratio of 1:1:2:1.
Then, for my delivery system, I liberally coat a mixture of nuts, and put them in a flip-top container and put that in my jersey pocket. I just pull them out and shake some into my mouth while riding. They taste great.
Perhaps I could market those under the names "Electronuts," or "My Salty Nuts."
Yesterday, I went on a "no food" ride, and put some of my mad-scientist powder in a plastic bag. I kept picturing the police stopping me and thinking it was cocaine, but that didn't happen, and I just ate a pinch of that stuff occasionally.
Let me know if my reasoning or math is faulty.