A colleague in my phd program went on the job market this year with research that is related to this, especially to the connection between writing and walking discussed in the final paragraph.
In a nutshell, his theory and experimental evidence suggest that we use the same cognitive mechanisms to process real maps as we do abstract maps. In particular, he shows that we often have mental "landmarks." He focuses on number lines as maps, and suggests that the round numbers behave like landmarks. He shows that all of the known cognitive signatures of the way we process landmarks on, say, a road-trip are present for these abstract landmarks.
He shows the same thing with textures in the context of anchoring and adjusting (we anchor on an initial texture and use it as a cognitive landmark.)
To me, his theory is extremely compelling and explains a lot. It makes sense that our brains, as our environments have become more complex, have adapted to use spatial cognition to process the abstract.
EDIT: Here is a link to his CV: http://marketingphdjobs.org/sites/default/files/Gaurav%20Jai.... The paper I'm talking about is called "Presence of Numerical Landmarks and Their Effects on Judgments." He hasn't posted it on the web, I'll see if I can get a copy from him and post it (if he's ok with me doing so.)
The method of loci (loci being Latin for "places") is a method of memory enhancement which uses visualizations with the use of spatial memory, familiar information about one's environment, to quickly and efficiently recall information. The method of loci is also known as the memory journey, memory palace, or mind palace technique. Many memory contest champions claim to use this technique to recall faces, digits, and lists of words. These champions' successes have little to do with brain structure or intelligence, but more to do with using spatial memory and the use of the method of loci.
Correlations have been found between memory and the playing of 3D video games, which also utilize our spatial memory. (Though wandering around in a video game is probably a subpar surrogate for doing the same thing in meatspace.)
I also recommend this BBC video of a persistence hunter tracking and running down a Kudu, just as an illustration of how walking/running, language/tracking, spatial memory, and planning/creativity are all tied together as a system that was once necessary for our survival:
After months I've been able to recall exact details about the random video I watched by returning to the same place inside the gameworld.
Kinda problematic if I listen to an unnerving passage in a place I enjoy visiting!
Here is an article with a description of the idea and an attempt to explain the mechanism: http://mobile.www.daysyn.com/Wardetal2008.pdf
Maybe related? But I also get the same kind of extra-sensory feeling when I copy data (doubly so if I cut data) -- like my hand is charged with something extra until I "unload it" by pasting the data. This has saved me many times when I get distracted at work mid-task, and before I go copy some new piece of data I can feel that I haven't pasted in the old data and go take care of that first. (I Wonder if anyone has done a study on this, and how many people experience something similar.)
New neurons. The next line about walking being easy tells me you live in a flat area with no obstacles.
"A small but growing collection of studies suggests that spending time in green spaces—gardens, parks, forests—can rejuvenate the mental resources that man-made environments deplete."
Uneven ground. I always look for uneven ground. Walking on concrete, man-made paths is the equivalent of looking at brick walls.
Unless you live on a mountain-top or near minefields, walking is still very easy compared to most other options except sitting and laying on a bed.
And even if you do live in such a place, it's usually pretty trivial to find a non-mountainous/non-obstacled path to walk in the surrounding area. Didn't say it has to be just next to your door.
But it is pretty easy once you get muscle built up and get used to the obstacles. I live in a mountainous area. I climb a fence daily and go over a bit of land with no concrete path - though admittedly everyday walking is on concrete most times. Going out into the countryside doesn't make it any more difficult.
There are hills, and then hills ~ https://www.flickr.com/photos/bootload/3957949381/
I'm the opposite; when I do run (which isn't often, now) I would rather run on a treadmill and listen to a podcast, or just music and zone out, and not have to worry about dodging obstacles or not being able to time my run.
I do love riding my bike around new places, though. I guess that's the same thing.
I also run a lot. And I do realize, my runs will be happier, if I don't constantly worry about pace. But can't help myself, not thinking about it. And all this despite being only a recreational runner.
In addition to helping make 30 minutes of sweating go by much faster, I find it almost always generates a bunch of ideas. Like a little brainstorming walk, if you will, but all-weather and easier to schedule.
My current favorite podcast for this is the Andreessen Horowitz "a16z podcast."
Meditating is harder(and coffee is helpful), but when successful, is much more satisfying.
So maybe there's a way to make chores more demanding of attention ? Like deciding to do them in a different way or focus on more/different details ? Maybe that's why the Japanese tea ceremony is so complicated ?
As drumming is , altough maybe there's something meditative about music?
This doesn't work all the time though. I believe there are limits to ones ability to influence it's mental state. Last year, very sick, I could sense the calming effect of meditation. But tonight for instance, after a violent incident, my mind is racing.
I have the paid version so im unaware if some/all of these feature require the paid version
Walking helps with difficult problems in coding and design. It helps because often when you get a bad idea that doesn't work, and you think it's actually a great idea, you still have twenty minutes left to walk. If you were sitting at the machine, you would be saying, "Eureka!" and coding the bad idea. If you're walking, you'd like to code the idea, but you can't; not yet. So you keep juggling the idea in your mind for the remainder of the walk, by which time you figure out that it was wrong.
If you get into a mode where you're just trying ideas to see what works, and in the given situation that approach isn't working well (however well it might work at other times) walking will physically remove you from that and break the pattern.
I've fallen out of the habit lately, but I was hitting the 10k target for a while. I have a sedentary desk job. So chores and playing with my kid got me up to about 3k. Then I'd walk for an hour during lunch to get another ~7k steps. Walking for an hour every day is fairly substantial commitment. I mean, it felt worth it. As you said, it's a huge productivity boost. I'm probably more productive walking 1 hour and working 7, rather than working a sedentary 8. It's not always easy to make that time in your day though.
I added the backstory, because I'm not questioning the value of the habit. I'm just always curious how much time people are devoting to walking when they talk about 10k steps.
Assuming you take one step every second (3600 steps per hour), it will take slightly less than 3 hours. One step per second is very leisurely pace.
I think consuming some portion of your subconscious with repetitive activity frees up some blocking on your conscious thought, so that you can stay engaged on an idea for longer. It's like your normal boredom/frustration loop gets muted by the repetitive behavior (music, movies in background, walking, fidgeting, etc.)
Sometimes having other things going on makes deep work easier, sometimes it makes it harder. I've noticed it's good to test both, and oscillate.
But within a couple minutes, I don't even notice, and I'm just letting my mind drift, sometimes to the extent that I've overshot my turnaround spot by more than a mile just from a lack paying attention
Having experienced this, I can't imagine now going back to the "old way" where I have random songs that differ every time, or different routes that require me to pay attention.
I've often thought the repetitive nature of the same route and the same music actually encourages the metal drift.
I often get the same energized writing vibe after a run. Though unlike the article emphasizes near the end, my 5 mile daily run is preplanned (obviously) and so leaves my brain able to effectively "dissociate" and enter that realm of creative thinking that often precedes our falling asleep. After the first couple miles, my body gets into the groove and I'm able to either serenely absorb my surroundings -- the geese and their Spring young, say -- or float around in that gooey reality between daydreaming and acting.
Steve Jobs was a particularly notable "hacker type" who enjoyed walks. So besides the article's writer bent, I'd say idle physical activity is a good choice for those who just want to think.
A walk through a park or a country path would be even better: greenery and nature has shown to boost creativity in some studies.
I used to run part of the way to school because I was notoriously late. At the end of the year I aced the gym class mile run, but overall my unreliability caused much concern in other topics. I maintained for a time that exercise is vital for a healthy mind, but because I didn't exercise on purpose, I couldn't take advantage of it.
But I wanted to mention this is completely reverse for me. Over the years I have found my body and mind are complete opposite side of each other. I have to complete stay moveless, and when I stay moveless for awhile that's when my mind will work at its extreme capacity. Moving, Walking, Talking, Writing, everything is kinda distraction from my deepest mind state, and I need that state when I study Math especially the hard/analytical problems. I call that deep state, ZEN. I wish I could be in that state everywhere and every day.
Two different types of thinking. Focused thinking where all your memory slots are consciously controlled. Un-focused thinking (diffused mode) where random connections between different ideas are made.  The unfocused thinking is where you get the ^aha^ moment. So yes I'd reckon every programmer/hacker/scientist/mathematician is pretty much doing what you describe.
 Barbara Oakley, PhD, PE., "Focused and diffuse modes of thinking- a brief on how it functions" ~ https://www.youtube.com/watch?v=dzjsk5e7srI
In my opinion, it's not necessarily about getting blood moving. It's rather about relaxed (a.k.a. diffused) thinking. Let it be driving a car on the highway, taking a shower or spending time in green spaces - both make our thoughts roam freely, thus, more creatively.
For me, the more important question is: why & how our thoughts start to wander around when we are doing such activities mentioned above. Is this default mode of human nature? How does our brain extracts "creative things" that we are never aware of in diffuse mode & where they come from?
Not sure about driving...maybe road-rage adrenaline?
Yes. I think it's because when walking or showering some attention is kept in the body. This matters for thinking purposes because new ideas signal their presence at an emotional level.
Whereas sitting at a desk one's attention is mostly in "in the head" and this is also why lengthy sitting at work or in front of the TV is unhealthy.
I may state the obvious, but it's about the blood moving inside the body and to the brain and such, not about mere movement of blood, body and all along with the vehicle to some destination.
 - https://www.versobooks.com/books/1865-a-philosophy-of-walkin...
I seem to achieve this sort of mental clarity when I'm on an open-ended recovery ride. Training days, however, are probably too regimented and my focus is solely on hitting and/or exceeding the targets set by my coach.
Does this explain why it seems all great cities have large walkable parks near their core downtown areas and near any areas considered to be more livable? It isn't the park, per se, but perhaps the ability to find walkable conduits that can be ambled without concern for bodily harm.
When I move to a new place one of the first things I do is locate the longest walkable circuit that does not involve busy intersections where waiting is required.
The Irish Nocturnes essay Meditation on Walking used to be online. Fortunately, the Way Back Machine has it.
[The Richmond Review was a nice early Web based literary magazine]
That is take a backpack and put like 35 pounds in it.
I highly recommend it.
The weight needs to be high up on your back and as close to your body as possible (there is some debate on this but in general that is what most people believe).
Also I don't have a citing on this but I'm fairly certain most people have back problems not from carrying heavy weight on their back but rather sitting down too much and picking up the weight incorrectly.
I recently picked up a GoRuck GR1  -- it's an amazing bag for everyday use. They also sell weighted ruck plates that fit the rucks and keep the load close to your body.
When subscribers read the New Yorker, they usually expect to have lengthy articles. There are plenty of bite sized, 30 second articles available practically everywhere on the internet.