Hands feeling heavy while chanting Shiv Mantra

I’ve noticed that while I chant my morning Shiva mantra with open hands halfway thru I start to feel my hands getting heavy as if someone placed heavy spheres on top of them and was wondering if this had any significance or meaning? Maybe it doesn’t mean anything and it’s just from sitting in cross leg posture for a long time but who knows there are no coincidences. Thank you for reading Namaskaram