How hard would it be to walk for 12 hours straight?

Would probably feel like running a marathon in a way.

I believe I could walk a marathon in less than 10 hours. Boston should open it up to everyone who wants to run and/or walk the route.

Can be done. Take a pack. Food, water, band aids, change of sox, even extra shoes. Feet, and bonking without food are your challenges.

I have run multiple 12 hour fixed timed events. If you don't know a fixed timed event is a type of ultramarathon where you run/walk for a specific amount of time (6hr,12hr,24hr, etc.) around a loop, a mile is the most common but I have done them on as short as a 400 meter track and as long as a 5K loop. I would sign up for one of those races if you're going to do this thing. Ultrasignup.com You will have people around you, aid, and lots of encouragement. If you are really walking/running a few hours a day then you are good. Do it.

It'll hurt the next day if you haven't done anything close to it before. DOMS and general muscle tiredness.

12 hours just walking around a track or park would be mind-numbing though. Why not hike somewhere interesting?

one time I hiked a peak called Khao Mokochu in western Thailand. A great hike. But very difficult to get permission to climb it and if attempting it without the necessary paperwork, there are a couple of ranger stations you need to ninja past in the early stages of the hike. So I started at 2am planning to get past them both before dawn. I got back at sunset at 18:00, so that's a solid 15 hours of walking, with a small backpack, because I took about an hour's worth of breaks. It was about 56km total with 1km or so of elevation gain. On the way back a ranger did come past me on a dirtbike, so I dived into the bushes and watched him pass none the wiser.

All great advice so far. Just to add:

1. Bring plenty of food/water (or a way to filter water),

2. Bring something to do. Do one thing for twelve hours straight is mentally draining, no matter what that “thing” is. Audio book, podcast, music, friends/family to talk to, a yo-yo, whatever. Doing something other than walking while walking will make the whole experience more enjoyable.

There are a lot of hikes you can do that will take 12 hours. It takes some people 12 hours to hike across the Grand Canyon. Find an interesting one near where you live. An out-and-back is ideal. Much better than just walking around some loop dozens of times.

I don’t think you’ll be able to walk 15 minute miles. Last Sunday I “ran” 57 miles in 13 hours with a total pace of 13:03/mile, that includes shoe changes, bathroom breaks in the ditch, and few rough patches with my knee.

I walked almost none before 20 miles, averaging about 9:45s to that point, over 100 minutes in the bank compared to your plan.

I could be wrong, you could be a fast walker and maybe walking is just so much less demanding than running that, although going slightly slower, you will never stop or have issues.

Keep us posted, I’m interested to hear.

Pro tip, bring along some ibuprofen and hydrate well.

ask the brave US Marines who survived the Bataan Death March what it was like to walk 12 hours. And then another 12, and another 12.

Stephen King wrote a book called The Long Walk back in 1979 about 100 teenage boys who were required to walk at 4 miles an hour and if they stopped they were shot dead. It's been a while since I read it, but IIRC, it was some sort of distopian future and the last survivor got... to survive?... I can't remember.

I try to do this at least once a month and it's great. I find the best meditation in the world though is done while standing on a river bank or beach with a fishing rod in my hand and nobody else around. Basking in nature with a soundtrack of water rippling or lapping on the shore...

It's very unlikely that you will walk 4 miles per hour for much longer than one hour. I would be surprised if you even get over 30 miles in 12 hours.

But just do it and report back.