not sure why i'm getting back pumps and sore calves/achil tendons/plantar fascia... but my lower legs feel awful when running, some temporary tingling/numbness on bottom of feet. and severe back pumps. this might just be my shoes wearing out, and some extra weight i'm carrying. i'll buy some new running shoes and see if that fixes the problem. i'm only on test, so i shouldn't be getting any unusual back pumps, as far as i know.