Free 16-Week Training Plan for Trail 100 Andorra by UTMB Trail 21K
Train for high-vertical Pyrenean climbing, technical descents, and mountain weather in a compact race window.
At 24.9 km with 1,350 m of elevation gain, this is a fast, punchy distance where speed and hill strength both matter. At 54 m of vertical per kilometer, much of the course is runnable — the plan focuses on building your aerobic cruising speed while preparing you for the steeper sections. The official cutoff is 6 hours, so pace management starts from week one.
Expected race date: Sun, 13 June 2027Open entry24.9 km · 1,350 mStart: 08:00
Use this date as a planning estimate
The organizer has confirmed the event window, but not Trail 21K's detailed start schedule. The plan currently uses the expected distance day.
I'm preparing for Trail 100 Andorra by UTMB Trail 21K. Here is the public training preview.
24.9 km · +1,350 m · 254 days to race day
Public preview only; my private routes and schedule changes are not included.
Plan: https://trailsplits.com/races/trail-100-andorra-by-utmb-trail-21k/training-plan?tier=strong-finish&strength=1&strength_track=no-gym&engine=unified&days=3
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Terrain autopilot
Find a matching route near you
We'll look for a loop near you that matches your next run (40 min · ~4.5 km · +150 m)
and rehearses the 54 m/km demand of Trail 21K.
Terrain intel
Expect rocky alpine singletrack, steep forest climbs, exposed ridgelines, and long descents back toward Ordino.
Weather & kit
June can be warm in town but cold, wet, or stormy higher in the Pyrenees.
What this plan focuses on
Build steep climbing strength before speed.
Practice poles on sustained ascents.
Add technical downhill sessions for quad durability.
Rehearse fueling during long hike-run climbs.
Prepare kit for rapid mountain weather changes.
Unified race plan · beta
Uses the same load, recovery and taper rules as race discovery, with course-specific climbing only because this course has verified elevation.
Use it for race-effort sessions and race day. Easy runs stay easy whatever the goal; the plan's efforts come from how you run now.
Your starting point
Not stated. The plan assumes a typical starting week for this race and opens at 3h 00m of running.
Fit the plan to your recent training
This schedule opens at 3h 00m of running and 375 m of climbing in week one and peaks at 4h 15m and 1,050 m in a week; the longest planned outing is 1h 40m. These are prescriptions, not proof of readiness.
Adjust this plan
Swap concrete training days, or mark a day done/skipped without changing the race-specific template.
Calendar subscriptions refresh on the calendar app's schedule. This calendar export uses the selected start date and includes weekly summaries and any pre-base sessions. Use Keep this plan above for a fixed copy of the displayed race schedule.
Route-aware workouts
Key sessions include route buttons that deep-link into the Planner with pre-filled distance
+ elevation filters.
Little downhill to prepare for; general strength still helps.
Peak week target
1,050 m
4h 15m total training time
Cutoff pressure
Firm cutoff
14.5 min/km average required. At an easy all-day pace the course takes about 5 h of the 6 h allowed.
Training emphasis: rolling aerobic speed, moderate hill repeats, and disciplined pacing.
Plan summary
The block begins on 2027-02-22, 20 weeks from now.
Duration
16 weeks
Start
2027-02-22
Peak weekly time
4h 15m
Peak weekly vert
1,050 m
Week 1Base Building
3h 00m ·
375 m vert
Mon · 2027-02-22rest
Rest
Effort: Rest
Rest or gentle mobility.
Tue · 2027-02-23hills
Easy hills + uphill strides
40 min · 150 m vert · ~4.5 km
Effort: Easy; strides strong but relaxed
Start with 10 minutes easy on rolling terrain. Then 6 x 20 seconds uphill strides, strong but relaxed, walking back down between them. Finish with at least 10 minutes easy; the rest of the run is easy on the hills.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-02-25easy
Easy run
1h 10m · ~9.7 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-02-27long
Long run
1h 10m · 225 m vert · ~8.2 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy on rolling terrain. Then 6 x 20 seconds uphill strides, strong but relaxed, walking back down between them. Finish with at least 10 minutes easy; the rest of the run is easy on the hills.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-03-04easy
Easy run
1h 10m · ~9.7 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-03-06long
Long run
1h 10m · 250 m vert · ~8 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy on rolling terrain. Then 6 x 20 seconds uphill strides, strong but relaxed, walking back down between them. Finish with at least 10 minutes easy; the rest of the run is easy on the hills.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-03-11easy
Easy run
1h 15m · ~10.4 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-03-13long
Long run
1h 15m · 275 m vert · ~8.5 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy. Then 6 x 20 seconds relaxed strides, with 1 minute easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-03-18easy
Easy run
1h 05m · ~9 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-03-20long
Long run
55 min · 225 m vert · ~6.1 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy on rolling terrain. Then 6 x 20 seconds uphill strides, strong but relaxed, walking back down between them. Finish with at least 10 minutes easy; the rest of the run is easy on the hills.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-03-25easy
Easy run
1h 20m · ~11.1 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-03-27long
Long run
1h 15m · 350 m vert · ~8 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy on rolling terrain. Then 6 x 20 seconds uphill strides, strong but relaxed, walking back down between them. Finish with at least 10 minutes easy; the rest of the run is easy on the hills.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-04-01easy
Easy run
1h 20m · ~11.1 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-04-03long
Long run
1h 20m · 375 m vert · ~8.6 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy. Then 4 x 6 minutes uphill at a hard but repeatable effort, with 2 minutes easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-04-08easy
Easy run
1h 15m · ~10.4 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-04-10long
Long run
1h 25m · 400 m vert · ~9.1 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy. Then 6 x 20 seconds relaxed strides, with 1 minute easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-04-15easy
Easy run
1h 10m · ~9.7 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-04-17long
Long run
1h 05m · 325 m vert · ~6.8 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy. Then 4 x 6 minutes uphill at a hard but repeatable effort, with 2 minutes easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-04-22easy
Easy run
1h 15m · ~10.4 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-04-24long
Long run
1h 30m · 475 m vert · ~9.3 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy. Then 4 x 6 minutes uphill at a hard but repeatable effort, with 2 minutes easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-04-29easy
Easy run
1h 20m · ~11.1 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-05-01long
Long run
1h 30m · 500 m vert · ~9.1 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy. Then 4 x 6 minutes uphill at a hard but repeatable effort, with 2 minutes easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-05-06easy
Easy run
1h 20m · ~11.1 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session B: step-downs (slow 3–4s), lunges/sit-to-stand, soleus raises, carries (backpack), dead bug. Quality reps; stop well before failure. Keep the slow step-downs at least a day away from a long run; if this session falls the day before or after one, swap them for core work. In peak weeks, keep it short and easy.
Sat · 2027-05-08long
Long run
1h 35m · 525 m vert · ~9.6 km
Effort: Easy
Build relaxed time on feet at conversational effort.
Start with 10 minutes easy. Then 6 x 20 seconds relaxed strides, with 1 minute easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-05-13easy
Easy run
1h 20m · ~11.1 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Start with 10 minutes easy. Then 4 x 5 minutes on familiar, controllable terrain at controlled hard, with 2 minutes easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-05-20easy
Easy run
1h 25m · ~11.8 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Start with 10 minutes easy. Then 4 x 5 minutes on familiar, controllable terrain at controlled hard, with 2 minutes easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Effort: Moderate: controlled reps, stop 1–2 short of failure
No-gym Session A: Bulgarian split squat, single-leg RDL, step-ups (bench/stairs), calf raises, side plank. Quality reps; stop well before failure. If 10 reps feels easy, add weight (backpack/water) so the last 2 reps feel challenging. In peak weeks, keep it short and easy.
Thu · 2027-05-27easy
Easy run
1h 25m · ~11.8 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Start with 10 minutes easy. Then 3 x 2 minutes at controlled race effort, with 1 minute easy between repeats. Finish with at least 10 minutes easy; any remaining time is easy.
Run the 24.9 km as planned: start controlled and use the fuelling and kit rehearsed in training.
Cutoff check
If your race has a time limit, this estimates the minimum average pace and whether your
target finish time clears the cutoff.
Result
Min pace: 14.5 min/km
Exports
Use the personal subscription URL for a live saved plan. Calendar links regenerate from their parameters and may reflect updated race facts or engine fixes. A kept plan and its downloads remain unchanged.
Disclaimer: this plan is general information, not medical advice. Adjust based on fatigue,
experience, and injury history.
About the Trail 100 Andorra by UTMB Trail 21K course
At 24.9 km with 1,350 m of elevation gain, this is a fast, punchy distance where speed and hill strength both matter. At 54 m of vertical per kilometer, much of the course is runnable — the plan focuses on building your aerobic cruising speed while preparing you for the steeper sections. The official cutoff is 6 hours, so pace management starts from week one.
This training plan adapts the 16-week structure specifically for 24.9 km with 1,350 m of elevation gain,
scaling weekly volume and vert targets so your body is ready for race-day demands.
Shorter trail races reward aggressive pacing and strong climbing. The plan emphasises quality intensity — hill repeats, tempo efforts, and race-pace sessions — while building enough endurance to finish strong on tired legs.
Training phases for Trail 21K
The current 16-week schedule has these phases for 24.9 km and 1,350 m of climbing:
Weeks 1–6 — Base Building: Establish consistent aerobic training and introduce course-like terrain gradually.
Weeks 7–11 — Vert Accumulation: Increase course-specific climbing while rehearsing easy effort and fueling.
Weeks 12–14 — Peak Volume: Practise the longest planned outings and race equipment without adding extra sessions.
Week 15 — Taper: Reduce training load while retaining a small amount of familiar intensity.
Week 16 — Race week: Reduce training and follow the race-day plan.
Pacing a runnable course
At 54 m of vertical per kilometer, much of the Trail 100 Andorra by UTMB Trail 21K course is runnable.
Training should emphasise aerobic cruising speed — tempo runs on rolling terrain, sustained effort on moderate climbs, and efficient flat-to-uphill transitions.
The biggest risk on a runnable course is starting too fast; practice negative-split long runs to build discipline.