I had my surgery nearly a year ago, L4/L5 microdiscectomy. Getting fit before hand is a great idea. It will aid your recovery. I was back on the bike after a few months. It will be difficult to start with, but just take it easy. I was back at work far too soon. Before my op, I only heard good things about it, then afterwards, only people not getting it done because of the risks. It worked for me, I was on a lot of tablets for 4 years, I got off them as quick as I could. Good luck with it mate. You might have some quite dark days, I did, but it does get better, try not to much back though. I did and came off and gashed my leg, was off the bike for another month, so be patient and it will be fine.