Hallo, Lisa,
We've all had cramp, but the cures are nearly as numerous as the sufferers. As I understand it what happens is that a muscle tries to shorten itself owing to what it considers to be abuse. In your case pulling or pushing against too great a resistance could be the abuse and the cure is not to stop doing it but to reduce the resistance, and then build back up. So use a thinner elastic or stop trying to pull it quite so far.
Most of us have the calf muscle at rest one, often some hours after exercise, maybe at night in bed. I think this is sometimes caused by the calf muscle lengthening to much when it has been under stress earlier. It reacts by trying to shorten itself and overdoes it. The only cure is to make a sharp angle at the ankle and to stretch it gently back to the right shape. All muscles are capable of being stretched back into shape but some are placed so that the cure is worse than the affliction. If that happens heaven help you. It happened to me once in the car while being driven from a marathon race. Both hamstrings and both buttocks went into convulsion and I had to get out and writhe in agony until I could get back in. On somebody's lawn.
Some people swear by upping the salt content of the diet or taking quinine. Indian tonic is not bad for this, preferably with added gin. This doesn't actually help but it could make the remedy more interesting.
I still think cramp can be avoided or reduced by not making sudden, demanding movements when you don't know the status of the muscles in question. Stretch first and then do the manoeuvre. When I was a kid people at my swimming club could swim length after length with no trouble but it was very common for otherwise fit people to be gripped by cramp during the water polo that followed. This is because of the sudden sharp movements that happen during the game.
Above all keep muscles warm. Remember the hideous legwarmers from the 70s and 80s? Maybe not such a bad idea when nobody is looking.
Sorry if this is a bit long and rambling. I hope that somewhere in there you can find something to help you.
All the best,
Alan