Free 16-Week Training Plan for Grindstone Trail Running Festival by UTMB 50K
Train for Appalachian climbing, ridge fatigue, and long night running without needing alpine altitude.
At 50 km with 1,550 m of elevation gain, this is an ultra-distance effort that demands careful fueling, pacing, and mental resilience. At 31 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 9 hours, so pace management starts from week one.
Expected race date: Sat, 18 September 2027Open entry50 km · 1,550 mStart: 07:00
Use this date as a planning estimate
The organizer has not announced the 2027 event date. The plan will move when the official date is published.
I'm preparing for Grindstone Trail Running Festival by UTMB 50K. Here is the public training preview.
50 km · +1,550 m · 351 days to race day
Public preview only; my private routes and schedule changes are not included.
Plan: https://trailsplits.com/races/grindstone-trail-running-festival-by-utmb-50k/training-plan?tier=strong-finish&strength=1&strength_track=no-gym&engine=unified
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September can be humid, stormy, cool overnight, and warm during the day.
What this plan focuses on
Practice night running on technical trail.
Build climbing repeat strength.
Prepare feet for humid conditions.
Use steady fueling through long forest sections.
Train descending on rocky ground.
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 4h 40m of running.
Fit the plan to your recent training
This schedule opens at 4h 40m of running and 500 m of climbing in week one and peaks at 7h 50m and 1,425 m in a week; the longest planned outing is 3h 20m. 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.
10.8 min/km average required. At an easy all-day pace the course takes about 9.5 h of the 9 h allowed.
That leaves little margin: a bad patch, the weather or an intermediate cutoff can decide the day, and more training buys less time on a course like this than it seems.For a first time, Grindstone Trail Running Festival by UTMB 21K on the same weekend is the safer choice.
Training emphasis: aerobic cruising speed, cadence control, and late-race leg speed.
Plan summary
The block begins on 2027-05-31, 34 weeks from now.
Duration
16 weeks
Start
2027-05-31
Peak weekly time
7h 50m
Peak weekly vert
1,425 m
Week 1Base Building
4h 40m ·
500 m vert
Mon · 2027-05-31rest
Rest
Effort: Rest
Rest or gentle mobility.
Tue · 2027-06-01hills
Easy hills + uphill strides
40 min · 175 m vert · ~4.4 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.
Wed · 2027-06-02easy
Easy run
40 min · ~5.5 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Practise the fuel, hydration and kit you intend to use; treat amounts as rehearsal, not a universal prescription.
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.
Wed · 2027-06-09easy
Easy run
40 min · ~5.5 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Practise the fuel, hydration and kit you intend to use; treat amounts as rehearsal, not a universal prescription.
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.
Wed · 2027-06-16easy
Easy run
45 min · ~6.2 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Practise the fuel, hydration and kit you intend to use; treat amounts as rehearsal, not a universal prescription.
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.
Wed · 2027-06-23easy
Easy run
35 min · ~4.8 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Practise the fuel, hydration and kit you intend to use; treat amounts as rehearsal, not a universal prescription.
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.
Wed · 2027-06-30easy
Easy run
45 min · ~6.2 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Practise the fuel, hydration and kit you intend to use; treat amounts as rehearsal, not a universal prescription.
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.
Wed · 2027-07-07easy
Easy run
50 min · ~6.9 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Rehearse race fuelling: about 40 to 80 g of carbohydrate an hour from early on, 400 to 800 ml of fluid an hour depending on heat and sweat, and sodium with it (about 300 to 600 mg an hour). Use what you will carry on race day and adjust to your stomach.
Start with 10 minutes easy. Then 4 x 5 minutes uphill at a strong, sustainable 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.
Wed · 2027-07-14easy
Easy run
50 min · ~6.9 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Rehearse race fuelling: about 40 to 80 g of carbohydrate an hour from early on, 400 to 800 ml of fluid an hour depending on heat and sweat, and sodium with it (about 300 to 600 mg an hour). Use what you will carry on race day and adjust to your stomach.
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.
Wed · 2027-07-21easy
Easy run
40 min · ~5.5 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Practise the fuel, hydration and kit you intend to use; treat amounts as rehearsal, not a universal prescription.
Start with 10 minutes easy. Then 4 x 6 minutes uphill at a strong, sustainable 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.
Wed · 2027-07-28easy
Easy run
45 min · ~6.2 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Rehearse race fuelling: about 40 to 80 g of carbohydrate an hour from early on, 400 to 800 ml of fluid an hour depending on heat and sweat, and sodium with it (about 300 to 600 mg an hour). Use what you will carry on race day and adjust to your stomach.
Start with 10 minutes easy. Then 4 x 7 minutes uphill at a strong, sustainable 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.
Wed · 2027-08-04easy
Easy run
55 min · ~7.6 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Build relaxed time on feet at conversational effort. Rehearse race fuelling: about 40 to 80 g of carbohydrate an hour from early on, 400 to 800 ml of fluid an hour depending on heat and sweat, and sodium with it (about 300 to 600 mg an hour). Use what you will carry on race day and adjust to your stomach.
Start with 10 minutes easy. Then 3 x 14 minutes on familiar, controllable terrain at a steady to controlled-hard effort, descending under control for about 8 minutes between climbs. 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.
Wed · 2027-08-11easy
Easy run
50 min · ~6.9 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Use race-like terrain where practical, but keep the overall effort controlled. Rehearse race fuelling: about 40 to 80 g of carbohydrate an hour from early on, 400 to 800 ml of fluid an hour depending on heat and sweat, and sodium with it (about 300 to 600 mg an hour). Use what you will carry on race day and adjust to your stomach.
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.
Wed · 2027-08-18easy
Easy run
50 min · ~6.9 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Use race-like terrain where practical, but keep the overall effort controlled. Practise the fuel, hydration and kit you intend to use; treat amounts as rehearsal, not a universal prescription.
Start with 10 minutes easy. Then 3 x 15 minutes on familiar, controllable terrain at a steady to controlled-hard effort, descending under control for about 8 minutes between climbs. 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.
Wed · 2027-08-25easy
Easy run
55 min · ~7.6 km
Effort: Easy
Conversational aerobic running. Keep easy days easy enough to support the key work.
Use race-like terrain where practical, but keep the overall effort controlled. Rehearse race fuelling: about 40 to 80 g of carbohydrate an hour from early on, 400 to 800 ml of fluid an hour depending on heat and sweat, and sodium with it (about 300 to 600 mg an hour). Use what you will carry on race day and adjust to your stomach.
Start with 10 minutes easy. Then 5 x 3 minutes at a strong, sustainable uphill effort, walking back down between them. Finish with at least 10 minutes easy; any remaining time is easy.
Keep this comfortable and finish with plenty in reserve. Practise the fuel, hydration and kit you intend to use; treat amounts as rehearsal, not a universal prescription.
Start with 10 minutes easy. Then 4 x 3 minutes at a strong, sustainable uphill effort, walking back down between them. Finish with at least 10 minutes easy; any remaining time is easy.
Keep this comfortable and finish with plenty in reserve. Practise the fuel, hydration and kit you intend to use; treat amounts as rehearsal, not a universal prescription.
Race Day: Grindstone Trail Running Festival by UTMB 50K
Effort: Race execution
Run the 50 km as planned: start controlled and use the fuelling and kit rehearsed in training. Fuelling: about 40 to 80 g of carbohydrate an hour from early on, 400 to 800 ml of fluid an hour depending on heat and sweat, and sodium with it (about 300 to 600 mg an hour). Use what you will carry on race day and adjust to your stomach. Afterwards: rest or walk for several days, then short easy runs only, with no hard running for three to four weeks, longer after a long mountain day.
Sun · 2027-09-19recovery
Post-race recovery
Effort: Rest or very easy
Prioritize rest, food, fluids and gentle movement; do not schedule a workout by default.
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: 10.8 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 Grindstone Trail Running Festival by UTMB 50K course
At 50 km with 1,550 m of elevation gain, this is an ultra-distance effort that demands careful fueling, pacing, and mental resilience. At 31 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 9 hours, so pace management starts from week one.
This training plan adapts the 16-week structure specifically for 50 km with 1,550 m of elevation gain,
scaling weekly volume and vert targets so your body is ready for race-day demands.
Ultra-distance trail races require a different approach to training than road marathons. Time on feet matters more than pace, and vertical accumulation is as important as distance.
This schedule keeps the longer outings on single days at the selected running frequency and starting load. It also includes regular easier weeks.
Training phases for 50K
The current 16-week schedule has these phases for 50 km and 1,550 m of climbing:
Weeks 1–6 — Base Building: Establish consistent aerobic training and introduce course-like terrain gradually.
Weeks 7–10 — Vert Accumulation: Increase course-specific climbing while rehearsing easy effort and fueling.
Weeks 11–13 — Peak Volume: Practise the longest planned outings and race equipment without adding extra sessions.
Weeks 14–15 — 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 31 m of vertical per kilometer, much of the Grindstone Trail Running Festival by UTMB 50K 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.