I started lifting weights Monday for power training. My arms are still VERY sore, especially my biceps. They are stiff and sore so that it hurts to straighten my arm. It was 3 days ago I lifted, and we did heavy weight, low number of reps.

Is it OK to hit the heavy bag while my arms are stiff and sore like this, or will it cause harm? Would it be better if I wait until my muscles recover before I do impact training?

I am just starting to lift, I remember when I used to lift weights a few years ago my muscles didn't get as sore and they recovered faster... I think I need to get used to it again...