could also be lack of electrolytes, especially with the very bad government advice of reducing salt intake.
Cramping has little to do with electrolytes or hydration
https://runnersconnect.net/running-...ion-electrolytes-help-treat-avoid-leg-cramps/
I suffer from very bad calve cramps, screaming out in the middle of the night and rolling around on the floor in a spams of pain. Night after night. But for me it only occurs a few days after I have stopped running, so I run every day. Been to several doctors and a couple od specialists, none of them suggest anything about hydration or electrolyte issues and suggest its a neural muscular issue, liekly form an impacted nerve in my spine. Exercise and running in particular compress the affected nerve which both causes the problem but is also the solution ironically. If I stop running for long enough the cramps go away but I'll get 10 days of hell. I normally have about 48 before onset after stopping daily exercising.
I never get leg cramps running but have when swimming, especially when kicking off the wall. Again, this points to impacted nerves and neuromuscular cause.