All of us who suffered during longer runs due to dehydration and subsequent fatigue will know that most issues were the result of electrolyte/glycogen stores depletion. It's normal. Once the fuel runs out, even the best engine will stop and the same goes for the elite level, let alone us, the intrepid amateurs.
So, how do you deal with it? There are plenty of solutions out there, some good, some great, some inferior. Many are expensive. I drink my own electrolyte drink, carefully mixed by my wife, tuned around my running requirements and body responses.
Do you take any such drinks at all? If so, do you find them helpful? Or Not? I'm as curious as ever.