This dovetails well with another hobby of mine, making BBQ ribs and brisket. I've always had a very high salt intake, and perhaps not-so coincidentally, consider myself remarkably heat tolerant during outdoor activity, be it cycling or home improvement work, my two primary outdoor movement modes. A quick search of that all-knowing omniscience known as internet tells me that salt IS a big part of heat and exercise performance. One article says some people lose up to two full grams of sodium per liter of sweat. That's 5 grams of salt, most of a teaspoon. Apparently the potassium loss by weight is about one tenth that of sodium. One article claims to have a way to measure one's own sodium loss via sweat, as it purportedly varies greatly by individual. Not being a fan of link promotion, the title is
"Everything You Need to Know about Sweat," by Andy Blow. A training and fitness site, it seems.

On a century ride circa 2002, they had Twinkies at a rest stop about sixty miles in. Skeptical of junk food, I tried one nonetheless. I was rewarded with fifteen minutes of youthful go-get-um, which evaporated immediately after. I think the grease made my joints feel better. So I still use them twenty years later, for what it's worth. I think the garbage assimilates as rapidly as anything elsee, but it's certainly no substitute for thoughtful whole foods based nutrition