I had surgery on my foot last summer and ended up taking 4 months off. I had already signed up for a marathon, so I felt pressured to try to come back quickly, but to also avoid reinjuring myself. Below is an excerpt from my post on a thread that described my efforts to come back, which were ultimately successful. This is probably a little on the aggressive side for someone without a pressing, immediate goal, but I think it lays out a generally good framework. For a frame of reference, I had surgery in May 2016, this post was from late August 2016, and I started running late September 2016.
Best case scenario is I can start running in a week, more realistic is 3 more weeks, but it could be even longer. For the first two months after my procedure, I didn't to anything. I have been allowed to cross train on a stationary bike for the last month, and I have been doing that 40-60 minutes a day, 6 days a week since. Simulated a tempo effort for the first time this week.
I went from about 146 pounds (my race weight) to 157.
My training was very consistent in the couple of years before the injury, probably averaging over 50 miles a week, with peak mileage of 100 (once) and low 80s quite a few times.
I started tracking my food this week and intend to get under 150 by the end of September, and get down to race weight by late-October.
I will stick with the stationary bike until I am cleared to run, unless I am cleared to do the elliptical before I am cleared to run, in which case I will cross train on the elliptical. I will continue to do tempo simulations and start working in intervals to get me up to max heart rate.
Assuming that I can start running by the middle of September, I will start with running 3 or 4 days a week, 4 to 6 miles a day, and will do that until mid-October, and will then build to 35-40 mpw by the end of October. I will use the elliptical during that time for additional aerobic time so that I get the equivalent of 50-60 mpw of aerobic effort. I will start tempo efforts on the roads mid to late October, and will simulate tempo and interval sessions on the elliptical until I get there. I figure my first race will be a local 5 miler toward the end of October.
I will slowly convert the simulated miles on the elliptical to real miles on the road so that I can get up to 60 mpw by early to mid-December, when I will run a half marathon to gauge my fitness.
I will then do the last 18 weeks of the Daniels marathon program, which I used for my past two marathons. I intend to peak in the mid-80s, but will get into the mid-90s if my body tells me it is okay.