I know there's a giant shred thread but I don't have time to trawl through so hoping you will indulge me 
I'm a size 20 and super unfit........will it kill me? I'm kind of wondering if I need to be a bit lot fitter before I even start.
I have G cup norks and the only sports bra I can find at the back of my drawer is a C cup (oh to return to those days!)......am I going to give myself 2 black eyes ready for the nursery run?
What do you wear on your feet to do it? I don't really have any proper trainers and really can't afford to buy any.
TIA.