Restonica Trail by UTMB
Restonica Trail by UTMB – RT100K
Cours Paoli, Corte, Corse → Corte
Race guide
Updated 18 July 2026
The Restonica Trail RT100K by UTMB is a 69 km mountain race that starts and finishes in Corte, the historic heart of Corsica, and climbs 3855 m into the granite high country around the Restonica valley. Despite the "100K" label, this is a 69 km course, and every one of those kilometres is earned: from a start at 426 m the route reaches a high point of 2227 m, spending long stretches above 1500 m on exposed alpine terrain. This is a race defined by a huge early climb, sustained time at altitude, and technical Corsican rock. With cut-offs beginning early on Saturday morning and a genuinely steep profile, it rewards runners who can hike strongly, move confidently over broken ground, and manage a full mountain day with only a handful of aid points along the way.
The course: from Corte into the Corsican high country
The RT100K is a loop of 69 km with 3855 m of positive climbing, beginning and ending at Corte (426 m at the start, 427 m at the finish). The route wastes no time heading up: the first checkpoint at E Padule sits at 1648 m only 7.2 km in, meaning you gain over 1200 m almost straight out of town. From there the course threads a high traverse through Aleri (13.1 km, 1578 m), Inzecche (26.6 km, 1710 m) and Ninu (29.8 km, 1747 m) before pushing on to the highest sustained section around Bocca a Soglia (41.7 km, 2010 m) and the race high point of 2227 m. The terrain is classic Corsica: granite slabs, boulder fields, scrub and exposed ridgelines rather than smooth runnable trail. With so much of the middle of the race held above 1500 m, the RT100K feels less like a long trail run and more like a full day of mountain travel. Corte itself, both the start and the finish, bookends the loop at valley level, so the closing kilometres bring you back down off the mountain toward the finish at 427 m.
Where the race is won or lost: the big climb and Bocca a Soglia
Two features shape this race. The first is the opening ascent to E Padule: gaining roughly 1200 m in the first 7.2 km, it is the single most decisive climb of the day and comes when the field is still bunched and adrenaline is high. Going out too hard here empties the legs for everything that follows, so treat it as a controlled hike-and-climb effort rather than a race within a race. The second decisive zone is the high traverse from Ninu (1747 m) up to Bocca a Soglia (41.7 km, 2010 m) and the 2227 m high point, followed by the sharp drop to E Grotelle - Chez Téo at 45.8 km (1377 m). That is more than 600 m of steep, technical descent on tired legs, and it is where quads either hold or blow. Runners who have saved something for this section, and who can still descend cleanly over Corsican rock at the four-hour mark of altitude, put real time into those who arrive here cooked from the early climb.
Pacing and fuelling: manage the cut-offs and the aid gaps
The cut-offs give the shape of the effort. Aleri at 13.1 km closes at Sat 06:40, Inzecche at 26.6 km at Sat 10:20, E Grotelle - Chez Téo at 45.8 km at Sat 14:40. The gaps between staffed points matter as much as the times: from Inzecche (26.6 km) you run roughly 19 km over the highest ground of the day to E Grotelle at 45.8 km, so leave each aid station carrying enough food and fluid to cover a long, slow, high-altitude stretch where refuelling options are scarce. Crew points at Aleri, Inzecche, E Grotelle - Chez Téo and Alzu let you stage supplies and swap gear, so plan around them: top up calories and water aggressively, and use Alzu at 56 km as your final reset before the descent back to Corte. Because the middle of the race is spent above 1500 m with sustained climbing, fuel steadily from the start rather than trying to catch up later, when altitude and technical ground suppress appetite and slow digestion.
Conditions to expect: altitude, exposure and Corsican rock
The RT100K spends the bulk of its distance high on exposed Corsican mountainsides, with a high point of 2227 m and long sections above 1700 m around Inzecche, Ninu and Bocca a Soglia. That exposure cuts both ways: on a clear day it delivers spectacular high-mountain running, but there is little shelter when weather turns, and mountain conditions at over 2000 m can shift quickly from hot sun to cold wind. Come prepared for a wide temperature range across the day and into the higher, colder sections. Underfoot, expect the granite and boulder terrain Corsica is known for: rocky, technical and slow, especially on the descents off Bocca a Soglia toward E Grotelle and again on the long drop back to Corte. Sure footing and comfort on loose, rocky ground will save far more time here than raw running speed. Study the checkpoint altitudes before race day so you know exactly where the sustained high traverse begins and where the big descents fall, and pace the early climb with the whole 3855 m of ascent in mind.
Race Restonica Trail by UTMB – RT100K with Crux
Get the strategy, fuelling and crew plan dialled for this exact course — built from the real route, climbs and cut-offs. Your first race is free.
Plan this race — freeCourse profile
Checkpoints & cut-offs
✓ Course data verified against the official source (2026-07-17) · official source
0 km · 426 m · —
7.2 km · 1648 m · —
13.1 km · 1578 m · Sat 06:40
26.6 km · 1710 m · Sat 10:20
29.8 km · 1747 m · —
41.7 km · 2010 m · —
45.8 km · 1377 m · Sat 14:40
56 km · 1581 m · —
69 km · 427 m · —
More races
More UTMB World Series
More in France
Similar distance (50–100 km)
Racing Restonica Trail by UTMB – RT100K?
Get a complete race strategy — pacing, fuelling, crew plan and the crux moments — built on this exact course.
Plan your race in Crux →Strava is your training. Crux is your races.