I can't tell you how long you will need... but I can tell you that at 4 weeks a desk job was nearly too much for me, and I wasn't up to performing demanding physical labor for 10+ hours at a time for more like 3 months. Sorry!! (I *could* do demanding tasks as needed - but I'd have to rest after half an hour to an hour of that sort of work.) On the other hand, some women do bounce back more quickly.
I was also told not to lift more than 10 lbs for 2 months, in case your camera equipment weighs more than that.