Hello i decided to start the couch to 5k after a recommendation from another site. anyway i currently weight about 17.5 stone and also dont own any running shoes(plan for next pay day) im just about managing the jog but feels like concrete smashing against more concrete and my shins are taking a beating. is it my weight? do i need the right shoes before doing any more? best thing i have is a pairs of converse and feel i will probably get a telling off from someone here. cheers!