aodhan, I'd never heard of that before. i would guess that you'd have to be training in an unhealthy way for that to happen. right? anyway, just from personal experience, if i get some exercise, especially on the first day, i don't get cramps. although mine have never been intense, i've stopped getting them altogether since i've started training regularly. if i don't have training that day, i make sure i jog, take a long walk or do some power yoga. i guess you could try training and see if it works for you.