A Trail of the Kings – Lake Toba by UTMB training plan prepares you to race on Samosir Island, in the middle of Lake Toba in Indonesia, through dense forest, rugged terrain and Batak heritage sites. The event offers four adult races in June, from 17 to 102 km, plus a kids’ run. Here are the official figures and how to train for Lake Toba, distance by distance.
The short answer
- Allow 6 to 8 weeks for Legacy Dash 17K, 10 to 12 for King’s Ascent 25K, 14 to 16 for Ultimate Expedition 60K and 20 to 24 for Caldera Crown 100K.
- Indicative peak weeks: 50 to 70 km and 2000 to 3000 m of climbing for the 60K, 70 to 90 km and 3000 to 4500 m for the 100K.
- Key sessions: long hills, power hiking, technical descents, long runs with lots of climbing and heat training.
- The defining feature: very vertical middle distances (over 50 m of gain per km on the 25K and 60K) in a tropical setting.
Contents
Lake Toba by UTMB distances and elevation gain
The event takes place in June on Samosir Island. Figures come from each race page on the official Lake Toba by UTMB website.
| Race | Distance | Elevation gain | Profile / notes |
|---|---|---|---|
| Caldera Crown 100K | 102 km | 4197 m | 100K category, 3 Running Stones; 30 h limit, the event’s longest course |
| Ultimate Expedition 60K | 64 km | 3236 m | 50K category, 2 Running Stones; 20 h limit |
| King’s Ascent 25K | 25 km | 1293 m | 20K category, 1 Running Stone; 7 h 55 limit, forest and lake views |
| Legacy Dash 17K | 17 km | 230 m | No Running Stones category; valleys below Pusuk Buhit, 4 h limit |
| Kids | 0.7 km | not published | Kids’ run (ages 7 to 12) with parents |
The courses cross Samosir’s signature landscapes: dense forest, rugged ground, lake panoramas and sites tied to Batak heritage. Legacy Dash winds through the valleys below Pusuk Buhit, while Caldera Crown, as its name suggests, tackles the high ground around the caldera. The official site gives no maximum altitude or detailed terrain breakdown, so rely on your race profile and GPX. In June, expect a hot and often humid tropical climate, with possible variation at higher elevations.
What makes Lake Toba demanding
The middle distances are surprisingly steep. Ultimate Expedition packs 3236 m of gain into 64 km and King’s Ascent 1293 m into 25 km, more than 50 m per kilometre in both cases. That is a mountain-race ratio and should be trained as such: plenty of power hiking, quad-heavy descents and cut-offs that leave margin only if you pace well.
Caldera Crown is slightly less dense (about 41 m per km), but 102 km and a 30-hour limit mean a night out for most runners. Humid heat, rough terrain and hydration management complete the picture.
How long should you train?
Legacy Dash 17K: 6 to 8 weeks if you run regularly. A gentle profile and the event’s entry point.
King’s Ascent 25K: 10 to 12 weeks with a real focus on hills. With 1293 m of climbing, treat it as a mountain race, not a simple 25 km.
Ultimate Expedition 60K: 14 to 16 weeks, after a 30 to 40 km mountain trail race.
Caldera Crown 100K: 20 to 24 weeks, with at least one 50 to 60 km finish and some night-running experience. Our guide on increasing trail distance safely helps you step up.
The phases of your training plan
Base. For a June race, your base is built in winter: easy aerobic volume, one quality session a week and two strength sessions focused on quads and calves.
Specific. In spring, over eight to ten weeks, weekly climbing rises and long runs move to steep, rough terrain. Test your fuelling and hydration in race conditions; our guide on how to fuel for a trail or ultra will help. Keep a lighter week every three or four weeks.
Taper. Two weeks for the shorter races and the 60K, three for the 100K. If you come from a temperate climate, arrive a few days early to adapt to the heat.
Key workouts for Lake Toba
Long hills. 4 to 6 reps of 6 to 10 minutes uphill at a hard but controlled effort. They build the climbing power the middle distances demand.
Power hiking. On steep slopes, efficient brisk walking beats forced running. Practise it on long runs, with or without poles depending on the rules.
Technical descents. One session a week on uneven ground to build ease and confidence.
Heat training. In the final weeks, a few easy runs with extra layers or in the warmest part of the day, plus precise hydration tests on long runs. Progress carefully.
For a plan built around your level and adjusted every week, the RunMotion Coach app, the official online coach of the UTMB World Series, accounts for elevation and your availability, with strength and recovery built in. Try it free for 7 days.
Build your race plan with Race Strategy
With steep courses and tropical heat, anticipating your splits and intake changes everything. Race Strategy by RunMotion calculates a kilometre-by-kilometre plan with pace adjusted for gradient, altitude and technicality, estimates split times at key points and provides a section-by-section fuelling and hydration plan (carbs, water, sodium). Import the official GPX of your race and adjust it to race-day weather.
Running Stones and the UTMB World Series
Lake Toba awards 3 Running Stones for Caldera Crown 100K, 2 for Ultimate Expedition 60K and 1 for King’s Ascent 25K. To fit it into your season, read our UTMB World Series training plan guide and our advice on planning your trail running season.
FAQ
Are poles allowed at Lake Toba?
Check the rules for your race. On the steep 60K and 100K they can help uphill if you have trained with them.
What level do you need for Ultimate Expedition 60K?
A 30 to 40 km mountain race finished in good shape and regular long runs with lots of climbing. With 3236 m of gain, it is closer to a short ultra than a short trail race.
How much climbing per week for Caldera Crown 100K?
At peak, 3000 to 4500 m a week is a common guideline for amateur runners, adapted to your history. If you live somewhere flat, use stairs, an inclined treadmill and strength work to compensate.
Final thoughts
Lake Toba calls for climbing strength, confident descending and real heat management. Mountains, vertical gain and ultras are home ground for RunMotion: our founders, twin brothers Guillaume and Romain Adam, come from the Alps. Start your free trial.
Article updated by the RunMotion Coach team.
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