Holding on to crash cymbals during Drill

The first time I hold on to the crash cymbals for the first marching/ drill, it was super duper tiring my arm muscles are super painful!! But the second time I do the marching I didn't feel any sores on my arms. We had our Drill Recording, it was going to end soon, but somehow my arms suddenly feel sore and I almost play the cymbals at the wrong pulse.. but luckily the recording was ending in a few seconds time. I was hanging there, not to play at the wrong pulse if not we had to retake it again.