More and more, it seems that the conventional wisdom on cramping is changing. No longer is considered just an electrolyte or dehydration issue, its a combination of factors that include extreme muscle fatigue and an overloading the nervous system. I’m seeing more and more evidence that its not the introduction of strong electrolyte sources (like pickle juice and mustard) that help reverse it quicker but its the strong flavor shocking the nervous system into resetting.
Thanks to decades of marketing, most athletes believe that cramping is due to dehydration or lack of electrolytes. However, dehydration is very rarely the cause. Research shows that cramping can and does happen in hot and cold temperatures, with no changes in hydration status or body water loss, and no changes in blood electrolyte levels. So then what is the cause?
Source: Trail And Ultra Running