Serpent Trail.
The 100K of the Serpent Trail covers the route end to end, from Haslemere to Petersfield through Surrey, Sussex and Hampshire. The two towns sit under 20 km apart as the crow flies, yet the course winds its way through the South Downs National Park. Preparing for it means preparing for a very long day: the hills fill the first half, and the final 40 km still have to be run.
Serpent Trail 2027: Course, Elevation & Route Profile
The start is in the Haslemere area, and the longest climb of the day begins as early as km 2: a little over two and a half kilometres up to the course high point at nearly 280 m. A short, steep ramp follows around km 10. For more than 20 km after that the route slowly gives up height without ever settling, reaching a little over 80 m at km 33.
The hardest stretch lies between km 34 and km 53. Four climbs of 50 to 100 m come in close succession, each followed by a long drop, the last of them to around 30 m at km 51. From about km 27 you share the route with the 75K, and from km 53 with the 50K as well.
Beyond km 60 nothing rises above 60 m: forty kilometres of small undulations into the finish at Petersfield. Throughout, the character comes from the rise and fall of the Wealden Greensand hills, from woodland and from river meanders. The course is marked with race signage, and 2027 is the race's 10th anniversary.
| Start | Length | Ø | Max. | Gain | Cat. |
|---|---|---|---|---|---|
| km 2 | 2.6 km | 5.2 % | 19.4 % | +132 m | Cat. 4 |
| km 10.1 | 0.5 km | 10.1 % | 20.1 % | +45 m | — |
| km 27.5 | 0.6 km | 6.5 % | 10.3 % | +40 m | — |
| km 34.4 | 1.3 km | 7.2 % | 14.7 % | +90 m | Cat. 4 |
| km 38 | 0.6 km | 9.1 % | 17.8 % | +50 m | — |
| km 46.1 | 1.2 km | 7.8 % | 15.9 % | +89 m | Cat. 4 |
| km 51.2 | 1.8 km | 5.4 % | 11.5 % | +99 m | Cat. 4 |
| km 58.8 | 0.6 km | 5.8 % | 8.6 % | +35 m | — |
Climb categories follow the road-cycling convention and rate the terrain itself (length and gradient) regardless of sport: Cat. 4 marks the easiest rated climbs, Cat. 1 the hardest, and HC (hors catégorie, “beyond categorization”) is reserved for the most brutal ascents. Short climbs below the Cat. 4 threshold stay unrated.
How to pace Serpent Trail.
Start under control
The long climb from km 2 meets you on fresh legs, and that is the trap. You can run it, and the ramp at km 10 as well, and the bill only arrives hours later. Hike both from the outset even if it feels unnecessary, then let the 20 km to km 33 roll by easily. The 100 m the course loses overall will not give you anything back.
Hold your rhythm
The day is decided between km 34 and km 53. The climbs there are short enough to invite overreaching, and the steep descents between them cost your quads more than the ascents cost your lungs. Hike everything steep and stay in control downhill. Reach the far end still running smoothly and you have a good race ahead of you.
Spend what is left
From km 60 no terrain forces you to walk any more, which is the second problem: for forty kilometres there are no natural breaks. Schedule short walking spells before you need them rather than running until nothing is left.
Training plan for Serpent Trail: 12-week build
Build the base
Age-group runners can expect roughly 11 to 16 hours. The effort is low and aerobic, but because hardly any stretch stays level for long it keeps shifting between hiking, jogging and running downhill. You are training less for a speed than for the ability to keep moving through an entire day.
Train race pace
The key session mirrors the order of the race: long runs of four to five hours with the hills saved for the second half, followed by flat ground that you make yourself keep running. Back-to-back long days at the weekend supply the pre-tired legs you will carry into km 60, and show you what pace still holds after that.
Rehearse the course
Descending strength counts for more than pure climbing power. Downhill running on woodland paths when tired, strength work for the quads and brisk uphill walking on 10 to 15 percent slopes belong in every week of the specific phase. At this distance the hike is no emergency measure; it makes up a large share of your race time.
Arrive fresh
Race day is 3 July, so your longest sessions fall in May and June. Use them to practise eating and drinking across many hours, and run with the organiser's route on your watch so that its winding line still feels familiar late in the day.
Courses
Download the Serpent Trail course as a GPX file for your watch or bike computer.
Let YOUB adapt your plan for Serpent Trail dynamically
Ben connects your goal, the course, current load, recovery, and calendar. Your plan stays pointed at race day even when real life is not perfectly plannable.
Everything about Serpent Trail.
How long is Serpent Trail?
Serpent Trail is 100 km long. That distance shapes how much aerobic endurance, pace durability, and race-specific work belong in the training plan.
How much elevation gain does Serpent Trail have?
Serpent Trail has around 1,514 m of elevation gain over 100 km. That affects pacing, muscular load, and preparation for late-race sections.
What is the route profile of Serpent Trail?
Serpent Trail is classified as Rolling, averaging 15.2 vertical metres per kilometre. 25% of the route is flat, 33% climbs moderately (2 to 6%) and 3% is steeper than 6%.
What climbs does Serpent Trail have?
The hardest climb of Serpent Trail starts at kilometre 2, runs for 2.6 km at an average of 5.2% and gains 132 metres. Cycling-convention rating: Cat. 4. 8 climbs are mapped in total.
Is Serpent Trail a loop course?
No, Serpent Trail is a point-to-point course: start and finish are in different places.
Is there a GPX file for the Serpent Trail course?
Yes. The Serpent Trail course is on this page as a free GPX download — ready to import into Garmin, Wahoo, Komoot, Strava or any other app that reads GPX.
How should I prepare for Serpent Trail?
Preparation for Serpent Trail should account for 100 km, 1,514 m of elevation gain, current training load, and available training time. An adaptive plan helps place key sessions without ignoring recovery and real life.
What pacing strategy works for Serpent Trail?
The pacing strategy for Serpent Trail should reflect 100 km, 1,514 m of elevation gain, and your current fitness. Start controlled and keep margin for sections where the profile or fatigue makes target pace harder.
When does Serpent Trail 2027 take place?
Serpent Trail 2027 takes place on July 3, 2027.
Where does Serpent Trail 2027 take place?
Serpent Trail 2027 takes place in Petersfield, United Kingdom.
Which distances does Serpent Trail offer?
Serpent Trail offers 5 distances — Serpent Trail 100K: 100 km; Serpent Trail 75K: 75 km; Serpent Trail 50K: 50 km; Serpent Trail 20K: 20 km; Serpent Trail 10K: 10 km.
How do I register for Serpent Trail?
Registration runs through the organiser: serpenttrailrace.com. YOUB shows you the course, elevation profile and training plan for your preparation.
