Timely article since I'm finishing my first two weeks.
43 years old, history of back surgery after a Jiu Jitsu injury, did CrossFit for 12 years, and have a good working knowledge of the lifts (loved watching Coach Rippetoe's video back in the day and owned the 1st edition of SS). Went through a very long period after back surgery 10+ years ago of reinjuring my back over and over until I met a chiropractor who identified severely atrophied multifidus muscles (said they were the size of a 7 year old girl's). Got those muscles stronger over several months. Was eventually back to snowboarding, Jiu Jitsu, and very short runs (3 mins of running, 3 mins of walking for a total of 30 mins.) Gave up the Jiu Jitsu and running and currently just doing the SS Novice program.
So far I've gained 11-12lbs in the first 2 weeks. I'm 6'2" tall, started at 185lbs and now 196-197lbs (and still have visible abs...for now!). I already look bigger, clothes are fitting tighter, and my lower back feels incredible. Only adding 5lbs to each lift each training session. Again, I'm 43 with a history of back surgery (L4-L5 / L5-S1 double discectomy and double hemi-laminectomy). Before the surgery I was at a point where I eventually lost feeling in both feet, lost a bunch of weight from being depressed and actually had trouble straightening out my right leg completely, and after exhausting every non-surgical approach I could find I got a myelogram. .It showed severe nerve root impingement I had surgery less than two weeks later. While they were in there they also removed a bunch of disc fragments that had broken off and was worse than they thought, but that's a story for another time.
Obviously still have pretty low numbers but steadily making progress and feel fantastic:
BS: 215
Press: 115
Bench: 215
DL: 255
So far the toughest part has been consuming enough calories and is proving to be harder than the workouts.