How Fast is too Fast? 6 Lessons from a Sub-80 Day Thru-Hike

I summited Mount Katahdin on September 4, 2023, and started heading south. On November 21, 78 days and ~2200 miles later, I reached Springer Mountain in Georgia. I think in some ways my experience was very different from a traditional northbound hike on the Appalachian Trail that starts in Georgia, finishes in Maine, and migrates from spring to fall. I wanted to share what it’s like to thru-hike the AT in this timeframe, with the unique joys and challenges of going fast and late-season.

Why 78 days?

The exact number of days was arbitrary, but I did set out from Maine with a goal of finishing around Thanksgiving. I chose to hike this way for a few reasons. First, I was intrigued by the challenge of big miles on rugged eastern terrain. I thought that there was a good chance I could do it, but I wasn’t sure. That unknown was part of what made tackling another thru-hike an exciting adventure for me. Second, I wanted to optimize the weather window and enjoy the Appalachians at their best: autumn leaves most of the way, less rain, no bugs. And finally, I had non-hiking goals that made completing the trail in a compressed timeframe appealing. In ‘real life’ I work as a lab technician and geologic researcher at a university. I have an amazing supervisor and people around me who make it possible for me to quit my job, go on adventures, and get rehired. However, I wanted to do fieldwork over the summer, and I am also applying to PhD programs with deadlines through December.

My preparation was just that I like to exist in constant motion. My job is part office, part lab, with several different spaces spread across four floors of a building. I run around New Jersey roads and trails when I feel like it, anywhere from 10 to 100 miles a week. I also started with some previous long-distance hiking experience. Last year, I did the Pacific Crest Trail from July to October. I’ve completed the Long Trail and accumulated a few hundred other miles on the AT, so I knew to expect the mud, rocks, and roots that would come with following the white blazes. I spent over a month this summer off-trail doing bedrock geologic mapping in Nevada and Colorado. I was poking around at 13000 feet in the San Juans, and flew directly from Durango to Boston to start the trail.

Irving Lake in the Needle Mountains (San Juans) in Colorado, five days before I started the AT. The lake is a few thousand feet above the nearest trail that runs along Vallecito Creek. Surrounding cliffs are made of the ~1.8 billion-year-old Irving Formation and the whole valley has been carved by glaciers.  The ridge of loose rock debris, on the far left side of the lake, is likely a moraine that accumulated on the edge of an ice flow.


Even with prior experience, I learned a lot about hiking the AT en route. Here are some of my big takeaways.

1. You will spend most of your time walking.

This sounds obvious. Most people who decide they are going to walk from Maine to Georgia plan to spend a lot of time hiking every day. But, here is some math that I didn’t do ahead of time, which I think might be helpful to someone else who is planning to attempt the AT at this pace.

Say that for the time you are out of camp, you average 2 miles an hour. This number has no statistics behind it. But it’s my guess for what I’d get by taking the average of scrambling up and down slick outcrop in the rain in the Whites, with cruising over a dirt path in the Shenandoahs, and throwing in some time for filtering water/digging out snacks/digging catholes/staring contests with deer, etc. The average time to complete the Appalachian Trail is about 170 days according to the ATC website. That comes to 12.9 miles, or 6.5 hours, per day. Most hikers will do more miles than this on many days, then balance it out with ‘zero’ or ‘nero’ days in towns or hostels. Those bonus days are weighted more towards the activities of buying and eating food, doing shower/laundry type chores, and hanging out than walking. By contrast, to hike the trail in 78 days, you have to go 28.2 miles a day every single day. So 14 hours. All other activities–acquiring/preparing/eating meals, setting up for the night, planning, loafing, and sleeping–must fit into the other (on average) 10 hours.

Going up the north side of Mount Moosilauke. The start of the ‘The Fifty’ maintained by Dartmouth’s Outing Club, Moosilauke was a turning point: I went from climbing to mostly walking and never went back to climbing the AT in the same way. Two miles an hour was a pipe dream in many spots to the north of here, in the rugged terrain of southern Maine and the White Mountains. But it was attainable, and almost always surpassable as long as I stayed in motion, to the south.


As I found out on the fly, this does not leave much time for other shenanigans. I had a few goals when starting the AT. One, obviously, was to walk to Georgia. Another was to do some work on grad school applications: revising and submitting a fellowship proposal, reading papers, and doing meetings over Zoom. I also planned to meet up with friends on the trail corridor, and take fun side quests when they presented themselves. And, yet another goal was to blog for the Trek. Fortunately, I like ambitious juggling games, and the first three things worked out great. Unfortunately, I dropped the ball on the last one…if it isn’t clear from my dinky three-post history.

2. You can cherry-pick your hiking season…

The one constant of Appalachian weather is change. ‘If you don’t like the weather, wait five minutes’ was something I heard growing up south of Boston, and I think it applies even more in the mountains. But there are some things you can depend on. If you start a northbound thru-hike in March, it will be cold in Georgia and you may get snowed on. It will be boiling hot and humid for a solid chunk of the summer through the mid-Atlantic. Mosquitos will come for your blood at some point, or at many points. Starting southbound in June instead? The infamous black flies will be there to greet you in Maine, and Vermont (aka, Vermud) will do its level best to suck off your shoes. And, you will still be stuck hiking in summer through the lower-elevation middle section of the trail.

I definitely felt welcomed by Vermont.

My golden ticket solution was to start in September. The flies and mosquitos were dead. Vermud had dried out by the time I got there–my experience in Vermont was especially incredible for this year, since many southbound hikers were forced to jump ahead or got off trail completely because of the historic flooding. For the entire length of the AT, the temperature stayed mostly between 30 and 65 degrees with just a few hotter days in the first week and colder nights towards the end. I did have some unseasonable wet weather in southern Maine and northern New Hampshire. But south of Vermont, there were only four nights total where I had to hide out under the roof of a trail shelter or hostel. I spent the rest of my time sleeping under the stars, and I didn’t get soaked or snowed on once.

Between Mount Greylock in Massachusetts and the Shenandoahs in Virginia, 600 miles of trail is entirely below 3000 feet. The memorial obelisk in the background marks New Jersey’s highest point, in High Point State Park, at a whopping 1800 feet.

The icing on the cake was chasing the fall leaves. Dots of fiery red maples appeared when I was still in Maine. I walked through the Shenandoahs in their full golden glory, joined by all the leafpeepers out on Skyline Drive. I went about 1500 miles in the autumn foliage before the leaves dropped during a cold snap in southern Virginia. I never walked the green tunnel on the AT; it was orange, red, and yellow, and then gone.

Sandy Bottom Overlook on Skyline Drive, a bit past sunrise. Sunny days in the 60s and smooth trail made the 100 miles of Shenandoah National Park fly by in a golden tunnel.

I think overall I was pretty spot-on about timing. With 20/20 hindsight, the only thing I might have done differently is start about two weeks earlier. This would still be late enough to avoid the bugs and most of the heat, and would have gotten me almost to the end of the trail before the leaves fell. It is surprisingly annoying to wade through leaves when they come up to your ankles or even your knees, and they hide all the rocks, roots, and holes so you have to trip on them to know what’s there. Also, daylight was in short supply by the end of my hike, and it would have been nice to hold onto a little more of it.

Late fall foliage at Watauga Lake in Tennessee was a welcome surprise in mid-November.

3. …But you can’t pick your hiking weather.

Like I mentioned above, I had several rainy days between the end of the Hundred Mile Wilderness in Maine and the Presidentials in New Hampshire. When I reached Mount Washington on a mid-September day, it lived up to its reputation of ‘the worst weather in the world.’ I got to the summit, slightly terrorized by inching along through miles of freezing rain and walls of wind that had started to pick up to hurricane force–past what I expected from the high summits forecast. And I was cold. In the Sherman Adams visitor center, I changed into every piece of dry clothing I had, but that is when I started shivering and it took me a long time to stop. Some impromptu trail angels made it possible for me to get off the mountain, and return the next day in one piece with improved respect for the fierceness of New England weather at 6000 feet.

Looking south towards Mount Lincoln from the summit of Mount Lafayette, along Franconia Ridge. After days of mostly walking in rain, I stood here and had a flash of comprehension: this is why people love the White Mountains. Skimming along the ridge between these peaks was like being in the Lord of the Rings or somewhere out west, and it was one of the most epic parts of the trip.

Other than Mount Washington, though, I walked all day no matter what the weather was doing. I wanted to because I love walking, but I also needed to, in order to make miles. Since I didn’t hold out for sunshine, I never saw more than a few hundred feet in any direction through the White Mountains north of Franconia Ridge. At Bear Mountain State Park, I didn’t get to go through the zoo because I was there before it opened. I was on McAfee Knob in a cloud and Dragon’s Tooth in the dark. For most of the Roan Highlands, both were the case.

McAfee Knob was engulfed in a cloud.

This may be my biggest regret of the way that I undertook my AT thru-hike. Because I didn’t have much wiggle room in my schedule, I passed through some of the most epic parts of the trail without seeing their best side. There is a silver lining, however. I think about hiking the AT as a buffet feast of the crown jewels of the eastern United States: two and a half months of indulging in Appalachian beauty. Having been to all of these places, I now have a mental bucket list of unresolved mini-adventures that I want to go back to. Luckily, I live in New Jersey, and I’m within driving distance of a lot of the trail. It’s actually a bright spot to look forward to during my post-hike return to reality. For example, I already have loose plans with my friend to road trip up to Pinkham Notch once the snow has made good progress melting out, to see the Presidentials for real.

Sunset from the top of Culver Fire Tower, NJ. New Jersey was one of my favorite sections of the trail–which surprised me–partly because of the gorgeous October weather, but mostly because this is my home turf where I sometimes go run around during real life. Walking here felt like coming home, except I got to go another 1300 miles before going back to work.

4. If you hike alone, you will be alone.

Here is another thing that at first might seem obvious: take off by yourself to spend months walking in the mountains, and you will spend a lot of time solo. Actually, this is not how the AT often works. It is a social trail. With thousands of people starting in Georgia each year, it’s common to quickly form ‘trail families’ with other hikers going through the same experience. Most people start their adventure alone, but many will rarely–if ever–camp by themselves. I experienced something similar when I hiked the Long Trail in August of 2021, which was my first extended backpacking trip. I didn’t really travel with other people during the day because I was going southbound (which is even less popular than going south on the AT). However, I didn’t sleep alone a single night. Mostly I stayed in shelters with several people and others in tents nearby. I embraced the company and felt more secure.

Interestingly, the more miles I have accumulated, the more I have found that I like doing my own thing. That worked out really well for this hike…it turns out very few people start the Appalachian Trail in September. I made it through the second half of the northbound ‘bubble’ in Maine, and met some flip-floppers scattered throughout New England. After New York, though, I met a grand total of five other thru-hikers for the rest of the trail: a couple in the Shenandoahs, and three people in the same day in the Grayson Highlands. I likely bounced over others, because I actually finished the trail at a pretty typical time for a southbound hiker. What I’ve found is that it’s rare to run into other thru-hikers while physically walking down the trail. Instead, people congregate at stopping places: trail shelters, hostels, and towns. Because I tended not to spend much time in these places, I hiked ahead of other people without ever meeting them. My introverted side reveled in the freedom of walking by myself all day then picking out a flat spot, far from other humans, to lay my sleeping bag for the night. And, each interaction that I did have was a treasure instead of a hassle because there were so few of them. In fact, I can list every time I had a full conversation in my final week on trail:

1. my hitch into Gatlinburg
2. a Zoom meeting and phone meeting while in Gatlinburg
3. my hitch out of Gatlinburg
4. with a man sleeping on a picnic table at 1am
5. Nimblerod at Around the Bend Hostel

On November 7, I met three thru-hikers and many ponies around Grayson Highlands State Park.

This is not to say that the trail was empty. Ultimately, not a single day went by on the entire AT where I didn’t catch sight of another human being. I frequently exchanged brief pleasantries with day hikers, weekend warriors, hunters, and grocery store clerks. The AT is a vibrant community around the best things in our country–the mountains and the woods–all connected by a 2200 mile corridor. That community never completely goes to sleep.

READ NEXT — The Loner’s Guide to Hiking the Appalachian Trail

5. You could resupply every day if you wanted to.

In a few places, this is an exaggeration. Right at the start of the trail, I went over four days through the Hundred Mile Wilderness before my first resupply in Monson. In others, it is not. In Massachusetts, for example, I encountered Stop and Shop north of Mount Greylock; my friend who took me out to breakfast; and Cumberland Farms in Dalton–all within less than 24 hours. In Connecticut, I was retracing my steps from two years ago, when I hiked that section with my friend. Then, we took over three days and carried our food the whole way. This time, in less than a day and a half I got food twice: at the Mountainside Cafe near Falls Village, then at the Bulls Bridge Country Store, while barely getting off the trail. Hiking big miles always makes logistics easier. And on the AT, the sheer amount of civilization is kind of wild. The trail often goes near towns or even straight through them. General stores, gas stations, and full-on grocery stores are right there or are a quick hitch away. The only planning ahead that I did for this trip was mailing two pairs of shoes to my friends, and the rest I made up as I went along. This was not the most time-efficient, but it was way less stressful to me than planning out resupply boxes and then the timing and places to pick them up. With the colder weather ensuring that nothing would go bad in my pack, I really enjoyed springing for prepared foods like a lasagna or a sandwich and having them the next day.

Hands down the best resupply on trail, acquired from my parents’ house near Port Clinton, PA. Homemade bread, cookies, and enchiladas.

Short food carries also helped me keep my pack weight down, which I think was important for not getting injured. Between not much food, no tent, no stove, and no trekking poles, I was traveling lighter than most other hikers I met.

6. It’s possible, and even fun to hike the AT in under 80 days.

Before I started, I had read about Heather Anderson’s extraordinary feat of endurance to set the overall self-supported speed record in her book Mud, Rocks, Blazes. Her FKT in 2015, at 54 days, stood for two years. When I realized that my goal timeframe would put me at about 80 days to complete the trail, I came up with a theory to reassure myself: it’s those last few weeks of difference between my speed and the record speed where fun gets lost and all the suffering takes place. My hike would surely be more similar to a 170-day experience than a 54-day one.

Now on the other end, I would say that my theory was a little optimistic…but overall actually pretty accurate. For my body, and my circumstances starting the trail this year, I found the sweet spot. I felt challenged but not overwhelmed. My body was sometimes tired but it never broke: I didn’t lose a toenail or even get a blister. I want to emphasize that this was my experience. I know of plenty of hikers who took their time and still got hurt or suffered way more than me.

I think the key difference between the way that I hiked the AT, and the way someone would go about setting an FKT, is that the trail didn’t absorb all of my mental energy. Sometimes I snuggled into my sleeping bag and read a paper before falling asleep. Sometimes when I went into a town, I got groceries and then sat for hours in a library or a cafe, thinking and reading or writing. My time spent not walking was more limited, but I still did other things and reveled in them perhaps even more because of it. I went to a bonfire in Vermont, hiked and camped with my friend in Massachusetts, spent the better part of a day with my parents, and even borrowed my own car in Pennsylvania. I met up with my friend’s friend’s dad and their dog, and I hung out with my aunt in Harper’s Ferry. I took small side adventures, things like hiking off trail a bit to snag a 4000-foot summit or an overlook at sunset.

I also want to mention here for transparency’s sake: I didn’t make it my priority to hit every white blaze. I know this can be a divisive subject. In fact, until I did the PCT last year, I would definitely have counted myself a purist–in terms of being determined to walk every step of the designated route that I set out to do. Wildfires changed that, and I am actually a happier hiker and person for the mindset shift: I look to have the most adventures while still putting in miles. In downtown Hanover, I walked all over with my friends, and only picked up the trail again to cross the Connecticut River. In the Shenandoahs, I night-hiked Skyline Drive to be under the wide-open sky with shooting stars and I watched the sunrise from roadside overlooks. A few times, when I was out of food, I popped out to a road so that I could run to get to town before a store closed. I am confident that I went 2200+ miles, but want to note here that not every step was on the AT.

I detoured to the top of a hill on State Line Road, NY near the NJ border to catch sunrise unobscured by trees.

During my many hours of night hiking, I started listening to music or podcasts aloud sometimes. Normally, I don’t listen to anything except the critters and the wind while hiking or running. I don’t carry earbuds. But it was nice to have the company and warmth of human voices in the long cold dark. My favorite was the FKT Podcast hosted by Heather Anderson (followed by Backpacker Radio, of course). And, at the very end of the trail, I decided to try out the purely-fast style of hiking just for the heck of it. It seemed like a fantastic thing to try being a part of this community whose voices emanated from my phone, people who were on a mission to be wildly adventurous and find out new things about the world.

Clingmans Dome was a popular place, even on a foggy November day. From here I took off on my last 200 miles in the mountains.

I departed Clingmans Dome, the highest point on the entire trail, with exactly 200 miles to go and a goal of completing every remaining step of the trail in 100 hours. I finished in 96. I hiked all of Georgia in one 28-hour chunk and set a benchmark for the female self-supported FKT. It was fun to end the trail this way, leaving my stamp on one very tiny part of AT history. Particularly as a solo, young female hiker going against the tide, I constantly got the question from well-meaning strangers and friends: ‘Aren’t you afraid?’. I loved seeing what I could do, and the freedom of being completely unafraid: of the dark, of being home alone in the mountains, or of searching out the limits of my body and brain. I still haven’t found them.

It was pouring rain and frigid when I reached Springer Mountain–one last hurrah from the AT.

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Comments 17

  • Pcs : Dec 8th

    Nice post…NJ rocks!

  • thetentman : Dec 8th

    Great post.
    And NJ does rock.
    Congrats on the hike.


  • GRIZZBEAR : Dec 8th

    THANK YOU so much for this post! I appreciate the fact that your thru-hike was neither a “typical” hike of about 5 months nor a FKT attempt – as you indicated, it was something in-between which is exactly what I’ve been contemplating. I feel you did a great job of accurately depicting the pros and cons associated with an accelerated hike. Nice work accomplishing your goal and again, thanks for sharing your experience with those of us considering something similar!

    • Isabel Koran : Dec 9th

      Thanks! Definitely, taking on the personal challenge and adventure of a faster hike is not just for record setters. Best of luck!

  • Ron : Dec 8th

    Great post and impressive work! I hadn’t thought about the weather (and bug) advantages of a later start SOBO hike! Did you have a tent north of Vermont? Thank you for sharing!

  • Isabel Koran : Dec 9th

    Thank you! Yep no bugs is a big one. When I hiked the PCT last year, the mosquitos in the northern Cascades with the snowmelt were the #1 demoralizing thing I’ve encountered.
    I mailed my tent home to my friend from Boston, on my way to start the AT, and ended up hiking the whole way without it. I was willing to do big miles to either get to some kind of roof or out-hike the rain. This led to a couple late nights of type 2 fun but was mostly good. It was honestly less about weight savings, and more just enjoying the ridiculousness of hiking over 2000 miles without a tent/loving cowboy camping.

  • Alison : Dec 9th

    Excellent post! Thanks for sharing all the detail.
    Best wishes on your applications/research–love to run into fellow geologists out there.

    • Isabel Koran : Dec 10th

      Thanks! I’m excited to see where in the world I (hopefully!) end up next.

  • Jingle bells : Dec 10th

    “Just exist in constant motion” and “oh btw I hiked the PCT quickly and I’ve done hundreds of miles already on the AT” don’t exactly go together. This post is incredibly hard to relate to. Most humans would be severely challenged if not outright legitimately endangered to average 28 miles a day, esp on the AT.

    • Isabel Koran : Dec 10th

      Yep, constant motion!

      Seriously though you have a good point: jumping straight into 20+ miles a day in Maine, without knowing your body well, is the perfect recipe for getting hurt. What I think is cool is that being prepared for an efficient thru-hike doesn’t require being an accomplished athlete or specifically training. It’s more about building up the physical and mental durability over time for long days on your feet–probably by spending long days on your feet.

  • Jam : Dec 10th

    I completely agree with everything, almost, given I’m doing a calendar 3x crown starting Jan. 1st. I’m wondering one thing. Why do we know?

    For example, when I finish, nobody will know, ever, only me.

    This means you completed your hike for an existential reason. I hope that it was worth it.

    • Isabel Koran : Dec 12th

      Definitely an existential question! Probably worth another post, another time. Best of luck with the calendar year triple, that is coming up fast!

  • John : Dec 13th

    Congratulations. The scientist in you really comes out in your writing. Best wishes for your continuing off trail adventures.

    • Isabel Koran : Dec 16th

      Thank you!!

  • Devil Dog : Dec 17th

    Love your post and especially your honesty. I bet there are a lot of thru hikers out there that didn’t hike by each and every blaze.
    Congratulations on your accomplishment.

    • Isabel Koran : Dec 18th


      That is true. It felt important to bring up my ‘blue blazes’ because of the context of claiming a fast thru-hike.


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