Anecdotally, I took a six-week layoff from running to (ultimately unsuccessfully) get over knee pain. In that time I made it a point to walk two or so miles each morning before work, and to hike a hilly route two or three evenings per week.
My first race after the layoff, having only gone on a few easy runs in the preceding two weeks, was a pleasant surprise. I even PRed at the distance. (Something perhaps can also be said for racing with low expectations.)
I also learned that fitness long gained translates to fitness long lost.
I attribute the good performance to being well rested and having fresh legs. I think the walking allowed my body the time it needed to rebuild the strength in my legs and knees that running for far too long through the knee pain had sapped in them. Now, although I've resumed partway my prior training volume, I continue to walk regularly. I also find it quite enjoyable and refreshing mentally.