I mean, anecdata, but after staring at a monitor from a chair all day, it really does my heart and brain good to go for a walk outside in my local preserve. I notice a big difference when I can't go for whatever reason (usually weather related). The preserve is quiet and peaceful in ways the local street is not.

But moving to within some distance doesn't mean they went walking there. I'm not sure how valid this study is. I think we've already done studies regarding sunlight exposure and just getting outside being good for you (assuming your environment is not bad). So was it just being outside made them feel better, and having the paths and whatnot made it more likely that they would go for a walk? Or even maybe just more likely that they take breaks? I know I'm terrible at taking breaks.

There's a controlled experiments that did show a pretty significant benefit to being outside in a forest vs. in an urban environment. The Japan one on forest bathing from Chiba University saw a 12.4% decrease in cortisol, 5.8% decrease in pulse rate and lower blood pressure for the forest cohort vs. the urban cohort under identical physical exertion parameters.

There was also one I found from back in 1984 where patients in a hospital that had a view of trees having a shorter stay vs. the group with the view of a brick wall, although not entirely sure that one was robust enough to draw any real conclusions on if view matters.

Just going outside in daylight in general should get you most of the benefits (in the right season, depending on where you live. Where I am in the PNW, midday light in the winter isn't even strong enough to trigger a lot of the benefits), so if your only option is to go for a walk outside on the sidewalk then do so, but there are even more positive benefits to be gained by being in nature, outside of an urban environment.