This is where everything comes together. After building your base of endurance and strength, the specific development phase immerses you in the real conditions of your target trail race. It’s the moment you shift from being “in training” to being “on a mission.”
Every session becomes a test. Every outing becomes a simulation. You’re no longer just training your body — you’re programming your race.
Understanding the Specific Phase
The specific phase naturally follows general development. You’ve built the foundation — now it’s time to sharpen the engine. The goal is simple: reproduce in training the exact demands of your race.
Elevation, terrain, duration, weather, fatigue, nutrition — everything must be tested, tweaked, and validated.
For a 30 to 60 km trail race, this phase typically lasts 4 to 6 weeks. For an ultra, it usually stretches over 6 to 9 weeks. It’s a demanding period: training volume increases, sessions get longer, and workouts become more targeted.
But it’s also the most rewarding phase — the one where you feel your body ready to absorb, respond, and climb again.
Key Training Focus Areas
The guiding principle is clear: imitate your race.
Endurance remains a core component, but now it’s mixed with elevation, fatigue, and duration.
Hilly long runs become essential. These are done on terrain similar to your target race, lasting 2.5 to 3 hours for mid-distance trails, up to 5 hours for ultras. This is where you test your fueling, hydration, gear, and poles. Nothing is left to chance.
Hill sessions are split into two categories:
Short, explosive hills (30 seconds to 1.5 minutes) to develop power and climbing technique,
Long hills (3 to 8 minutes) to build muscular endurance and sustain effort over time.
You also include climb-descent combinations with no rest, mimicking the muscular stress of technical terrain. You learn to push after a climb, descend with control, and manage fatigue.
Threshold and VMA workouts help maintain speed and improve your ability to hold a strong pace. These aren't the focus but serve as important reminders for sharpness.
Lastly, downhill work becomes a cornerstone. Your quads must absorb impact, stabilize your body, and react to terrain. This skill is built — and earned — through practice.
Strength Training & Proprioception Matter
In this phase, strength is your best ally.
One to two strength sessions per week are essential. Focus on lower body and posterior chain: squats, lunges, step-ups, planks, wall sits, and unilateral work.
This isn’t the time to build — it’s time to consolidate. Maintain strength without adding unnecessary fatigue.
Meanwhile, proprioception and mobility still play a vital role: balance drills on one leg, band exercises, stability postures. These small details make a big difference when fatigue hits at kilometer 50.
Managing Intensity and Load
Balance is key.
On average:
70% of training at low intensity (easy endurance),
20% at moderate intensity (threshold, race pace),
10% at high intensity (explosive hills, VMA).
This distribution protects the body while encouraging adaptation. Hard workouts should be spaced out with easy runs or active recovery days for proper absorption.
Sample Week – 30 to 60 km Trail Race
Monday: 1-hour easy trail run
Tuesday: Short hill session — 2 sets of 8 × 1-minute climbs, downhill recovery
Wednesday: Active rest or cross-training (bike, swim, cross-country skiing, yoga)
Thursday: Threshold session – 3 × 10 minutes at tempo pace with 3-minute recovery
Friday: 30-minute strength training + 40-minute easy run
Saturday: Long hilly run (2.5 to 3 hours), with power hiking and nutrition practice
Sunday: Downhill technique session – multiple repeats on steep slopes focusing on control and reacceleration
A balanced week combining power, endurance, and technical work. Around 8 to 10 hours total, adjusted to your level.
Sample Week – Ultra (60 to 100+ km)
Monday: Full rest or mobility session
Tuesday: 6 × 5-minute uphill intervals at 85% max HR, downhill recovery
Wednesday: Easy trail run or hike (1.5 hours)
Thursday: Strength or deep core training
Friday: 1h15 run with 40 minutes at marathon pace
Saturday: Long run (4 to 5 hours) on race-like terrain with poles
Sunday: Second long run (2 to 3 hours) — a shock weekend to build mental and muscular resilience
This advanced setup prepares the body for real ultra fatigue. Weekly volume can hit 12 to 15 hours, with reduced “assimilation weeks” every third week.
Tailoring the Phase to Your Profile
If you’re a beginner, 5 to 7 hours a week is enough. Focus on quality and consistency. One long run, one hill session, one threshold session, and some light strength work is a solid base.
If you’re intermediate, increase volume slightly and add a shock weekend to test mental stamina. The goal: hold the distance while staying sharp.
If you’re advanced or pro, this is where you play in the big leagues.
Add double sessions, night runs, mountain or altitude blocks. Simulate race-day conditions exactly.
But remember: without recovery, it all collapses. Assimilation weeks are as critical as training load.
Building Your Season Around This Phase
This is the time to switch into race mode.
Identify your main race and center your prep around it.
Schedule one or two tune-up races to test your strategy — without draining too much energy.
Plan your peak training load 3–4 weeks before race day, then begin tapering to arrive fresh.
Specific development is where you shift from preparation to precision.
You’re no longer training just to run — you’re training for that race, with its terrain, its duration, and its challenges.
In Summary
The specific phase is the beating heart of trail race preparation. It transforms your endurance base into race-day performance.
By combining long runs, varied hill sessions, downhill work, strength training, and smart recovery management, you create the perfect conditions to perform.
Run on your race terrain. Eat what you'll eat on race day. Wear your gear. Simulate your fatigue.
This is where you become truly ready — physically, mentally, and strategically.