I wasn't too unfit before I started but found it quite intense, and still do to be honest.
The upside is that I have become A LOT fitter, lost nearly a stone and am getting quite nicely toned now. I'm 34, had 3 kids, and this summer for the first time EVER I will wear a bikini on holiday and not feel too self-conscious!
On top of that, it is an excellent form of self defense. It is scarily effective and will give you the confidence to stand tall and fight back should you, god forbid, ever need to.
My friend was attacked on the way home on new years eve by a guy in the middle of the night and managed to kick him in the crown jewels and got away. This was one of the reasons I signed up for Krav Maga in the first place!
I don't now but I used to, and did it for about 3 years.
I wasn't hugely fit at the time but I think if you were completely unfit you might find it tough to start with.
Bruising you do have to accept. You can wear pads on your forearms and shins but you are likely to end up with some bruising anyway, especially on your thighs - although I did a Mixed martial art sparing class as well so was more or less permanently bruised from that.
I trained twice a week.
I would say give it a go. You do have to be unafraid of getting hurt, and not be shy about pairing up with a bloke to do grappling, but it is great fun and will give you loads of body confidence.
I am dittering whether it might be the sport for me? Do any of you do Krav Maga and if so, how fit do you need to be/how hard is it and more importantly do you often get visible bruises? Also how many times a week does one need to practice?