Doing feeds at Farm Sanctuary got me in shape. No doubt. My housemate told me that once during a feeds shift she wore a pedometer and clocked her mileage at 12 miles. I typically did feeds five days/week, logging me more walking miles than I typically ran when training for an ultra. Needless to say, I slept well.
On my last day there I lugged along my camera. Got about half way through before my battery died, so I missed a few barns (namely, the cattle). But you get the idea.