Anyone walk a fair amount (3-6 miles daily or more) in addition to running mileage?

it helps with the breathing if you have an office type job

I would say on some days I walk 2-3 miles around my facility. 6 miles is a heck of a lot of walking if you aren't a mailman.

I don't count it towards any fitness or running training. After you do it a few times a week, it doesn't become noticeable in your training.

The big place where I think walking has a place in training is on big uphills, really steep stuff of several miles. Even if you're super fit on the flat stuff and rolling hills, if you're not used to mountain running your heartrate will shoot the roof trying to run up stuff like that at even an easy pace. It's tough to put the ego in check for a while but I think it's beneficial to walk at first on that sort of terrain and slowly adapt to it until you can run the whole thing at a very easy effort.

Dick Mahoney, 2:14 back in the late 70's walked all day (mailman) and ran 140 per week.

Additional walking is very beneficial, to building bone density and injury prevention.

I walked about 6 miles a day back in college from walking multiple 1 to 1.5 mile trips from on campus dorms or off campus apartment all over a large campus and the nearby village center every day from morning to night. I enjoyed the wandering around all day with stops to class, eateries, library, student union, etc., but it was also somewhat of a necessity. Most areas of campus are closed to cars (I didn't own one anyway), and bikes were supposed to be walked on the main walkway.

I was a crazy runner who wasn't on the university running teams but ran 90 to 140 mpw on my own. I don't know if walking that much helped or hurt performance, but I remember having really tired legs walking to the first class each day, especially when going up the long stepped walkways. In my training runs, my legs would be sluggish for the first 30 to 45 minutes of a run before they would suddenly start feeling good. But that was more likely because I was often doing 15 to 20 miles runs every day in singles, rather than just the walking.

My tempo runs and time trials were always faster during school than during the summer when I was home and not doing all that walking. Overall during that time period, I improved from a 4:46/10:00 1M/2M in high school to 29:xx in solo 6 mile time trials, so I improved a lot with the help of - or despite walking that much.

Based on old threads here, Japanese runners training in CO are often seen putting in a lot of walking miles.

When I started running in the 7th grade I used to walk home after practice (about a 2.5 mile walk) due to lack of transportation. By my frosh year my mode of transportation had upgraded to a bicycle, so I would bike about 5 miles a day in addition to running 65-70mpw.

Helpful but not efficient if you can run instead.

100+ years ago lots of walking was the way they prepared for distance running from the mile to the marathon.