Interlaken, CH · September 2026
Jungfrau-Marathon
Jungfrau-Marathon pacing strategy with effort-based splits, nutrition timing, and course-specific risk notes for the 42.195 km mountain marathon.
- Distance
- 42.20 km
- Elevation gain
- 1944 m
- Typical temp
- 5–18 °C
- Cutoff
- 6:30:00
The short version
A brutal course
- ▸Big climbing day — 1944 m up. Pace the ascents on effort, not the clock.
- ▸Most runners crack near km 32 — fuel before km 30, not at it.
- ▸Full overhead sun from km 28 — sunscreen and run the shaded side.
Next edition
12 September 2026
Typical race-day conditions
5–18 °C
We lock the real forecast into your plan in race week.
Course difficulty
BrutalDriven by 1944 m of climbing, altitude up to 2285 m. Harder than Javelina Jundred (10.0), easier than Lavaredo Ultra Trail (10.0) — tougher than 85% of the races we cover.
Race data quality
Medium confidence
Last verified: 24/05/2026
Headline climb and distance are suitable for preview. A precise climb-by-climb profile should be imported before high-confidence paid positioning.
Elevation profile
Verified profile
Paid strategy guardrail
Official race packet remains source of truth
Step 1 · Free preview
See the course-adjusted plan first
Enter one recent result. The preview returns course cost, first splits, and fuel target from the deterministic engine and the current course data model.
VDOT
49.1
Estimate
4:30:04
Course cost
+76:20
Fuel target
90 g/h
First 5 km preview
full race locked
- km 14:56
- km 24:52
- km 34:44
- km 44:48
- km 54:47
First race free · then €7 Race Pass · no monthly subscription
Uses an approximate course model; verify final logistics against the official race packet.
Step 2 · Your full Jungfrau-Marathon plan
The preview shows the shape. The plan races it for you.
Course preview
Free
what you see now
- ✓Difficulty score & course data
- ✓Course-cost & toughest km
- ✓Your first full plan free, ever
Race Pass
€7
one-time, this race
- ✓Every km split, weather-adjusted
- ✓Nutrition & fluid timeline
- ✓Heat, wind & sun race tactics
- ✓Danger zones + watch file (GPX)
- ✓Race-week forecast & reminders
Annual
€19
per year, every race
- ✓Everything in Race Pass
- ✓Unlimited races, all year
- ✓Re-plan as your fitness changes
No subscription required — one race is a one-off €7. Cancel anytime on Annual.
Continue with approximate course data →Course elevation
1944 m total gain · 238 m loss · max 2285 m, min 560 m.
Fly the course
Sun & shade
Sun in your eyes
18 km
Sun on your back
5 km
Side / overhead
19 km
From km 28 the sun sits high overhead — peak UV and radiant heat, so keep sunscreen on and run the shaded side of the road where you can.
Approximate — solar position from the route geometry and a 08:30:00 start (timezone estimated from longitude), for a mid-pack finishing time.
Aid stations
8 stations on course — plan your fueling around them.
Race overview
Jungfrau-Marathon is a classic alpine mountain marathon from Interlaken toward Kleine Scheidegg. It is not a flat marathon problem: the late climbing and altitude make effort-based pacing essential.
How hard is this course?
Reference table — how the Jungfrau-Marathon compares to a flat sea-level course for four typical fitness levels. Computed from the route profile, mean course altitude, and typical race-week climate (12 °C / 70 % humidity). Your personal strategy uses your VDOT, per-km splits, nutrition timing, and the typical climate baseline for this static sample; paid strategies use Open-Meteo when a verified race date is inside the forecast window.
| Runner | Flat-course finish | Jungfrau-Marathon finish | Course cost | Adjusted pace |
|---|---|---|---|---|
| Beginner (VDOT 35) | 4:16:08 | 5:57:03 | +39.4% | 6:11/km |
| Intermediate (VDOT 45) | 3:28:17 | 4:50:21 | +39.4% | 5:02/km |
| Trained (VDOT 50) | 3:10:41 | 4:25:49 | +39.4% | 4:36/km |
| Competitive (VDOT 60) | 2:43:24 | 3:47:46 | +39.4% | 3:57/km |
Reference nutrition
For a 70 kg runner finishing in 4:25:49 at 12 °C. Adjust to your weight and tolerance — these are ISSN-window targets, not prescriptions.
- Carbs / hour
- 90 g
- Total carbs
- 399 g
- Fluid / hour
- 640 ml
- Sodium / hour
- 500 mg
FAQ
How should I pace Jungfrau-Marathon?
Treat the preview as an effort plan, not a fixed road-marathon pace table. The course model includes 1950 m of climbing, so climbs, descents, heat, and aid-station timing matter more than average pace.
How reliable is the current course data?
Headline climb and distance are suitable for preview. A precise climb-by-climb profile should be imported before high-confidence paid positioning.
Get your personalized strategy
The numbers above are samples. Sign up free and get the full Jungfrau-Marathon strategy from your VDOT, the current course model, Open-Meteo race-week forecast when available, and your nutrition preferences.
First race free · €7 per additional race · €19/yr for unlimited
Get my Jungfrau-Marathon strategyRelated races
- Eiger Ultra Trail E101· Grindelwald5912 m gain · typical 5–22 °CJungfrau-Marathon vs Eiger Ultra Trail E101 — which is harder? →
- Swissalpine Davos K68· Davos2600 m gain · typical 4–20 °CJungfrau-Marathon vs Swissalpine Davos K68 — which is harder? →
- Zürich Marathon· Zurich0 m gain · typical 4–13 °CJungfrau-Marathon vs Zürich Marathon — which is harder? →
- TCS Amsterdam Marathon· Amsterdam0 m gain · typical 10–16 °CJungfrau-Marathon vs TCS Amsterdam Marathon — which is harder? →
New to trail and ultra pacing? Start with our trail and ultra pacing guide or run the VDOT calculator.