Pretty much. :pinch:
Printable View
If you stop swimming then the cramps should stop. Don't do anything physical and go back to just sitting in the dark in front of your PC. Then only your head will hurt when your brain cramps.
Idol's diagnosis is correct.
To easily verify the truth of it, swim using the other leg only.
The resulting physical spectacle will amuse any onlookers, as well.
Win.