Ax, I've been giving them "exercise" too, but also weirdly unsure if it would stress them out. Probably just being paranoid though.
I guess the question in the first post is... is it even possible for ball pythons to have low muscle tone, unable to constrict prey properly? I assumed that snakes almost have a fixed inherent level of muscle tone/strength. Is intentionally strenuous "exercise" or "practice constricting" even necessary? aka, other than just letting them slither around on the ground and on your arm and such LOL.