Race Report: JFK 50

by Jackie Merritt, Milestone Sports Athlete


The JFK 50 mile race and its storied history holds a special place in my heart. The course runs through the same woods that I played in growing up. It’s the race I grew up following as a kid before I knew anything about running. It was the first ultramarathon I ever ran and was really the catalyst for my love of trail running and the trail community. I had run the race four times and this year I was returning to my hometown race after a five year hiatus.

There are a number of reasons why I had not returned to race JFK in the recent years, but primarily it was because after finishing the race in 2012, I told myself that next time I showed up I was going to run that 50.2 miles in under 7 hours. At the time I had just finished in 7:32, completely spent. I had no idea if I was even capable of accomplishing this ambitious goal, so I kept it to myself. Over the years I felt myself grow more and more, and get faster and stronger than I had ever known I could be. This year I became cautiously confident I could do this. I signed up.

Training leading up to the race was not perfect, for reasons largely outside of my control. Grant deadlines and work conferences consumed me for most of the two months leading up to the race and I was unable to keep my mileage up where I wanted it. Still, every single run that I was able to get in, I made it count. I averaged only 60 miles per week but was getting in a lot of quality sessions, especially track work and tempo runs.  Maybe the extra “rest” (or extra stress?) did me good because I have never run faster times in training than I did in those couple months before JFK. Speed is a critical element for doing well at JFK, so I told myself this could only be a good thing. I had the endurance; speed is what I needed most.


After a couple of restful days at my parent’s house, about a mile from the starting line in Boonsboro, Maryland, I felt ready to race. I had a plan for sub-7, but it was going to take flawless execution. JFK can be easily broken into 3 distinct sections:

1) 15.5 miles on the Appalachian Trail 
2) 27 mile on the C&O canal path
3) 8 miles on rolling road

The plan was simple: cover the first section in just under 2.5 hours (a very conservative estimate), then run 8 minute/mile the rest of the way, picking it up if I was feeling really good. In previous years, I had run the canal section consistently at 8:30 minute/mile pace the entire way, and it gets hard. Really hard. Running 30 seconds per mile faster than my former best was going to be a gamble, so I knew I needed to keep things in check early if I wanted to survive.

Five minutes till the gun


THE RACE | November 18, 2017

Section #1: Appalachian Trail
The gun fired and off we went, grinding up the first long 2 mile road climb to the start of the Appalachian Trail (AT). I was running with another woman in 3rd/4th place when we hit the AT. We bounced back and forth a few times going up the second long steep road climb. Finally at mile 5.5 we got to the good stuff – the rocks! I cruised over the first technical section pretty quickly and pulled into 3rd place, where I would sit for quite some time.

I love this section of the AT. It’s my happy place. Gently rolling single track with a net downhill to the canal. I felt good enough that I was pumping the brakes a bit so I wouldn’t get too carried away so early in the day. I passed a few guys over the next several miles who looked a little less comfortable to be running over the rocks, especially downhill. It’s not that long of a section, but many people underestimate how technical the AT gets. I enjoyed those couple hours in my element on the trail. I knew it wouldn’t last forever!

When I descended Weaverton Cliffs right before the canal stretch and saw my crew for the first time, I felt fresh. Without slowing down, I swapped out my hydration pack for a handheld bottle. Every minute in this race counts! I hit the canal in 2:19, ahead of my plan and putting a few minutes in the bank.

Descending from the AT


Section #2: C&O Canal
Time to run a flat 27 miles! This stretch may appear to be easy. It’s not. When you start running at a given pace, there is just no reason that you should ever slow down. No hills to “hike” or even trees to hide behind. A common mistake at JFK is going out too fast on the canal. I did not want to fall into that trap. I made myself run without looking at my GPS watch for that first mile. I normally do not race with GPS watch in trail races, but I thought it would be a useful tool for a race like JFK if used carefully. Still, I wanted to let my own perceived effort drive the pace and not become a slave to the satellites. I felt my watch vibrate for the first canal mile. 7:53. Perfect. I fell into a rhythm and the work felt comfortable. I ran on, clicking off the miles all within 3 seconds of each other until I saw my crew again at Antietam, mile 27.


When I rolled into Antietam, I was happy and knew this would be a good day. Matt W, who was there helping my parents crew, told me that Sabrina was 12 minutes in front of me and that I looked to be moving faster. I had no idea exactly how much faster I might be moving, if at all, but making up 12 minutes in 23 miles is a lot of time at JFK. I took in the information but did not consider deviating from my plan. I swapped out my bottle on the run and headed out without breaking rhythm, my next mile was just as fast as my last 12 had been.  

I would see my crew for the last time at Taylor’s Landing, mile 38. As I entered ultra-distance territory, the miles weren’t coming quite as easily anymore.When I felt fatigued, I thought about leg swing and drawing strength from my hip extensors and core instead of arching my back and using my hip flexors to overextend my stride. I became solidly focused on execution. 7:55, 7:55, 7:55, 7:55. It was almost erie how machine-like I felt.  

I realize that I had been drinking my normal amount (which is a lot) and it was much colder out than my system was used to. I was not sweating nearly as much as normal, which is probably the reason I had to stop to pee seven times in the race up until this point, which is pretty unusual for me! Each time I had to stop, I worried that I might not be able to find my rhythm again. But I always did. I reached my crew at mile 38 and Matt told me that Sabrina was now 6 minutes ahead, and that he calculated she was running 8:30 minute/miles for the last section. I grabbed a new bottle and bolted out of the aid station.

The math was simple. Six minutes to gain, gain 30 seconds per mile, 12 miles to go. If we both kept running at the exact same speed, it would take me exactly 12 miles to close the gap. This thing could come down to the wire. 7:43. Yikes, maybe too soon? I calmed down a bit. A light cold rain had started. Even on the cold day, it felt refreshing. 7:50. 7:49. 7:50. I finally came to the turn off the canal and onto the final road section.

Section #3: Rolling Roads
The road section starts with the notorious big hill. It’s short and steep and it never feels good. I didn’t know how my legs would be able to recover from it but within a minute they did. 7:34. I knew I was within reach of that sub 7 hour finish, but barely. The rain had turned to sleet and the wind was picking up. Soon it was heavy, freezing rain. I like running in the cold, but this was bone-chilling freezing cold. All I could think was just how thrilling this race was becoming. Like something from a movie! 7:36. My contacts were blurring, my eyelashes were freezing shut, and my face and mouth were so numb that it had become physically impossible to drink out of my bottle. I started aiming the bottle at my face and squirting in the direction of my mouth. 7:37.

Finally, at mile 47, through the freezing rain and blurry vision, I saw her. I caught up within a couple minutes and passed to move into 2nd with 2.5 miles left. I knew I could hold on just a little longer…

Then, pretty suddenly, at mile 48.5, both of my quads and my calves started cramping badly. Badly enough that I could feel the my running gait pattern change. I was surprised, because I have never had that problem before in any race or training run! It may have been the extreme cold (and being severely underdressed for it) or maybe just running on a flat path and road for so long. Whatever the reason, it took just about everything I had to push through that last mile and a half. But I held on.

The sleet and rain let up a bit as I finally rounded that familiar left turn and saw the final stretch into the finish line.

2nd female
sub 7 hour

32 minute 50 mile PR!

My 50 mile PR was 7 years old, set at JFK in 2010. I have broken every PR I had in every distance since that time. Man, I really wanted to get that one!! Based on my training and lead-up into this race, this really was the best possible outcome I could have hoped for. Great races and PR’s don’t come very often, but when they do they are even better when they happen in your hometown!


** Bonus #1: Biomechanics data! **

JFK data summary at a glance. The race is supposed to be 50.2 miles long hugging every turn on the AT, so the Pod-measured distance is pretty accurate. I’m most proud of my leg swing and Runficiency Score™ for staying strong for 7 hours! This took a lot of focus and work in training but I have found good running mechanics to be crucial for my stamina in ultra distance races.



Check out how things change over the 3 distinct sections of the race – pretty cool! The longer you can sustain efficient running mechanics, the easier those fast miles will feel at the end!



Rate of Impact – my arch nemesis! The trail running on the AT a few miles after the start helped me keep my ROI low on that section. I was mid-ROI for the entire canal section, which could use some improvement, but it’s at least consistent! The only high ROI I had all day was when I started running right after getting slammed by the big hill climb at the start of the road section. I was really fatigued! Then I got my running gait back in check and held strong for the last few miles into the finish.  


** Bonus #2 – Gear! **

PodPowered Saucony Kinvaras (start of race)


Happy trails!


Author: Jackie Merritt

Jackie is an accomplished ultra-runner and an avid MilestonePod data fan. She has a Doctorate in Physical Therapy and a PhD in Biomechanics. She lives and trains in Atlanta with her husband Jeff and the Yeti Trail Runners. When not running, Jackie works as a PT and research scientist at Emory University School of Medicine. Jackie also runs for Hoka One One and NATHAN Sports.