There is a prednisone induced myopathy that can happen with high dose, or long term use. I'm not sure about the inflammatory. I think the studies show it's more likely over 5 grams. Your well under that.

I agree you should notice strength within a few days. It will stay in you for a few days after you stop taking it as well. I think 5 days.

If you feel worse or side effects get too bad just call your doctor before deciding to tough it out.