Running 50 Miles on the Serpent Trail

I recently completed my first 50 mile (80km) trail run, set mostly over the Serpent Trail here in England. Running 50 miles is now an accomplishment I can put behind me, as I focus on my next goal: 100km, (62 miles).

My first 50 miler was quite hastily planned. I was physically prepared for it, but like the other shorter ultra marathon distances I have run before, I set my sights on the goal just a couple of days before.

I’m not sure exactly why I do this, other than it seems that I get sudden bursts of enthusiasm for goals. My best chance of completing these goals comes if I commit quickly to the task at hand after receiving the burst of enthusiasm.

Running 50 Miles – The Planning

Shortly after writing my previous post, Setting New Goals, Kilimanjaro and 100 KM / Mile Ultras, I figured an interim step between my previous furthest distance (65km), and my 100km goal was around 80km. That is 50 miles.

There was a weekend approaching and I had time to take a Friday off from work, so I did just that.

Thursday evening after work, with the help of my wife, we prepared two food and water packs. I plotted two markers on the trail I planned to run (Serpent Trail, in the South Downs National Park, England) for the support packs.

Re-fill Packs

I drove out that evening and hid the food and water packs off trail. I hung them from tree branches so as to keep them away from any curious or hungry critters.

Each pack contained:

  • SIS Electrolyte Tablet infused water (1.5 liter)
  • 1.5 liters of bottled water to refill my soft running flasks
  • Peanut butter bagle
  • Ella’s kitchen baby food pouches (game changers!)
  • Oreo cookies
  • Salt and vinegar chips/crisps
  • Tuna & Mayonnaise pasta
  • Sun screen

Running Hydration Pack

Of course I also had a hydration pack filled with goodies too. I had another ella’s kitchen baby food pouch, a few different fruit and granola type snack bars, 1 liter of water, a package of salty crisps, a pack of rice puff snacks, and a few assorted sweets.

running 50 miles hydration pack

How It Went

I woke up at 5am on the morning. Being summer, there was a bit of light out. I could tell the weather would be touch and go though as the skies were overcast.

My first priority was getting some food in me. I had some oat porridge (mixed with blueberries and honey) to get me going. I also wanted 45 minutes or so for the food to settle before I started out.

breakfast oats with blueberries

As mentioned before, I had prepared all my gear the previous night.

My footwear of choice were my (battered) Hoka Speedgoat 4 trail shoes. In hindsight they weren’t a great choice, but only because of how worn out they are. I’ve put in over 1000km on them and the uppers have holes worn in them. This proved to be a major water ingress problem on the trails later…

hoka speedgoat 4 trail running shoes
Those holes worn into the uppers were not good for the water and mud to come.


Leaving early meant the air was cool and things were pretty easy going. I struggled to keep my pace slow at first. I was trying to focus mostly on keeping my pace at around 6:00 per km. The first 12km of running was pretty flat as I made my way to Liss.

From Liss the elevation started to pick up as I ran up to Hill Brow on the long hill leading up there. From Hill Brow I entered the official Serpent Trail (tail route) at about 18km.

The trails were really wet from the prior day’s rains and morning dew. It was at this point that things started getting tough.

Between 20km and 30km I completely soaked my shoes and socks. The tall wet grass was inevitable through some of the long farm fields. There were also long unavoidable areas of mud and slush through the trails throughout the day.

The holes in my trail shoe uppers only made the problem worse. I kept going though, doing my best to ignore my wet socks and discomfort around that.

Passing one of my refill point stashes around the 25km mark, I made a point of drinking as much of my water as I could. Even though it would be uncomfortable sloshing around in my stomach as I ran, I wanted to stay hydrated as best as I could. I was already dripping sweat everwhere as it was starting to get quite humid.

My stop was just for 5 minutes to refill my soft flasks and down some electrolytes. I grabbed a peanut butter bagel from my pack and continued running, taking small bites as I ran along. This allowed me to get some calories in whilst not getting too uncomfortable eating as I ran.

Early and Late Afternoon

The afternoon led to the sun peaking out here and there. There were more farm fields to get through, and many more woodland and forest trails.

farm fields
At least this farm field had a bit of a trail through and wasn’t as overgrown as others.

I passed through the old town of Petworth at the 44km mark, still feeling pretty strong, though the constantly wet shoes and socks had become really annoying at this point.

The sun did help to dry out long grass on the trails. I had some spectacular views of the surrounding South Downs leading down towards Petworth, and again going up the hills out of Petworth.


At the 49km mark I hit the point at which I would begin my return route. But first I needed a refill. This is where I had stashed my second refill pack the night before. Hanging in a tree of a quiet forestry area, off the beaten path.

Ripping open the pack, I drank about 700ml of fluids here and refilled my two soft flasks. I tucked into some pasta, demolished two “Ella’s kitchen” baby food pouches (delicious), ate some salt and vinegar crips, and a couple of small cookies. It was my plan to not linger any longer than 10 minutes, as I knew that my muscles and joints would start locking up otherwise. I set off again within 10 minutes.

The return route basically doubled back on the way I came, all the way up to Hill Brow, which was the 50 mile (80km) mark.

Things started to get tough after about 60km. The constantly wet socks meant the skin on my feet was really wrinkled up inside and felt like it was starting to break. The sun was beating down on me and my water reserves were dwindling fast. I really should have had another water refill point somewhere around Petworth. My calf muscles were aching too, but I was able to mentally block out the pain.

Knee joint pain and fatigue was setting in and the kilometers felt like they were ticking over really slowly at this point. The trails were still just as wet and muddy later on in the day, now with the combined humidity discomfort.

I eased off the pace and switched to alternate each kilometer with fast walking the tough sections and running.

Coming back down through the forest and rough trails toward Hill Brow my water had run out. Giving up at this point was not on the cards as I was deep into the trails for vehicle access. The thought did cross my mind though. I must have been about 74km in at this point and was struggling with my wet and wrinkled feet being in pain along with near dehydration. I was close to the 80km mark and with a combination of alternating fast walking and slow running each kilometer, I reached my first refill pack again. I downed the remaining water and eletrolytes I had left in this pack earlier in the day and continued on to finish.

With just a mile or two remaining before I completed my running 50 mile challenge, and having replenished my fluids I felt a second wind. I finished the remaining distance feeling stronger than I had felt the previous two hours. A sign (to me at least) that I can do more.

Planning Ahead

I’m very happy to have checked off my “running 50 miles” goal. It’s a great step toward my next goal of running 100km (or 62 miles). I feel that as long as I keep up my monthly training mileage and prepare my route and refills a little better next time, 100km should be achievable!

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