I started running after Christmas....I'd always fancied it too and although it's hard to begin with, I love it! Firstly, buy a decent non-underwired sports bra....M&S do a great range of high impact bras that you can try on to get a really comfortable one. Next, get yourself fitted for proper running shoes, do not try running in just normal trainers, as you will have inadequate support & could injure yourself. Google your area and I'm sure there will be somewhere local to you where you can go for a fitting...plus they don't cost any more than a good pair of trainers either. The next step is to take it slow....start off with just speed walking, then add in short runs (about 100 m) in-between walks and build up slowly, so over time (weeks), you will slowly increase the distance you run vs the distance you walk. If you just start running you will hurt yourself & that'll be the end of it. Again, Google 'how to start running', there are lots of great sites packed with useful tips to get you going. I can now run for 25 mins at a time, compared to just a couple of minutes at a time when I first started...may not sound like much but being as unfit as I was, I think I have made great progress. As Mixxy says, running/jogging certainly gives your joints a hammering, so you could mix up runs with visits to the gym, where you could do some training on the treadmill, which is much kinder to your joints...perhaps even consider investing in one? I was lucky enough to get a great second hand one from a friend & I use it at least 5 times a week now, it's been invaluable. On the plus side of running though, is because it is high impact, it helps increase bone density...women who have had a bypass are at a much greater risk of osteoporosis, so running is great to countact bone thinning! Good luck! xx