Unless you're toeing the line against Patrick Makau, I really think the average person will get by just fine with a normal diet and simply remembering to drink a lot after a hard effort. I've done a good deal of research and reading on Kenyan distance runners and have always come away absolutely amazed and humbled by how casual they are about their diets, training regimens, etc. They eat regular whole food, not too much, and drink a lot of water. Supplements are alien to them.
I think we tend to SERIOUSLY overcomplicate things out here.
I speak from experience here. I went through Running Overcomplication Syndrome BIG TIME when training for my first marathon (Mind you, I completely failed on that first marathon attempt, didn't even make the starting line. I was so wracked with different forms of training anxiety and injury, my first marathon didn't happen until the following year, only after I learned to relax and start to run the way that felt natural to me). I was out slogging 12 minute miles with a heart rate monitor on, checking my splits, watching my "zone", listening to beeps on the watch, timing my calorie and fluid intake, obsessing over electrolytes, worrying about my footwear, strapping on Batman-like utility belts full of gels and fluorescent colored fluids...
I seriously started feeling like an absolute chump. Those days are over for me (well, I do often still feel like a chump, but for other reasons now). Since when did it become so complicated to simply go out and run or take a hike?
Kenyan schoolchildren would be chuckling at us.