Sport performance

Trail and ultra training plan: vert, descents, eccentric legs

phase.fitness plans trail running on effort rather than pace, counts vertical gain as the load that matters, trains the descents on purpose, and keeps two heavy, eccentric-leaning strength sessions until the final two weeks.

Updated

A trail runner on a mountain path with peaks and cloud behind
Photo by VANNGO Ng on Pexels
Level
Intermediate
Length
12–20 weeks
Days per week
5–6
Modalities
CardioStrength
Equipment
Trails with real climbing, a watch; poles if the event allows them; a gym or dumbbells
Sessions go to
Garmin, Intervals.icu, Strava, Hevy

The short answer

A trail or ultra plan in phase.fitness is built from the trail-running document its generator reads: a base of easy running on trail with power hiking practised on gradients above 15–20%, a build with uphill intervals of 4–6 × 3–5 minutes and one dedicated descending session a week, and a peak with long sessions to 60–75% of race duration that rehearse pack, poles, shoes and fuelling. Strength is 2 sessions a week — single-leg, calf and Achilles, eccentric quadriceps — reduced to 1 in the peak, with heavy eccentric work removed in the final two weeks.

Descending is the damaging half, and it is trainable

Most trail plans are road plans with hills added. The document phase.fitness reads starts from the opposite end: on a course with 2,000 metres of climbing the quadriceps fail on the descents, not the ascents, and eccentric tolerance is a trainable quality with its own progression — duration before gradient, gradient before speed, one session a week, never in the final two weeks because the soreness is delayed.

Intensity is enforced by effort, not pace. An easy run on a climb means walking sections of it; above roughly 15–20% gradient walking is faster and cheaper, and the transition between running and hiking is rehearsed inside long sessions so it holds under fatigue. Vertical gain, not distance, is the load phase.fitness tracks across the block.

Should I train with poles before an ultra?

If you intend to race with them, yes. A phase.fitness trail plan rehearses the kit in the peak phase: long sessions run to 60–75% of race duration with pack, poles, shoes and fuelling used exactly as they will be on the day, so nothing is tried for the first time in a race.

Is power hiking part of ultra training?

Yes. phase.fitness prescribes power hiking on gradients above 15–20% and practises it inside the long runs from the base phase onwards, because on a steep climb it is faster and cheaper than running. It is trained deliberately rather than treated as what you do when running stops working.

How long should the longest run be before a 100K?

phase.fitness builds the peak long sessions to 60–75% of race duration rather than the full distance, with the climbing and the descending the course will have. Heavy eccentric quadriceps work comes out in the final two weeks, so the legs that arrive are the ones that can still take the descents.

What phase.fitness builds

A program is a sequence of phases, each with a job. These are the phases phase.fitness writes for this case, with the bands the generator has to respect — transcribed from the document it reads, not invented for this page.

Base

4–8

Build

4–6

Peak

3–4

Taper

1–2

Each block is as wide as it is long. The numbers are in the table below.
PhaseWeeksJobBand
Base4–8Easy trail running with vert, power hiking inside long runs~80% low intensity by effort; strength 2×/week: single-leg, calf/Achilles, eccentric quads, trunk
Build4–6Uphill intervals, one descending session a weekUphill 4–6 × 3–5 min hard, jog or walk down; descents: duration → gradient → speed; strength heavy and low-volume
Peak3–4Long rehearsals, fuelling practised every long sessionLong sessions to 60–75% of expected race duration; strength 1×/week; no descending exposure in the final two weeks
Taper1–2Arrive with fresh quadricepsVolume down 40–60%; no heavy eccentric work

A sample week

One week from the first phase, as it would sit on the calendar. Your own week follows the days you say you have — 5–6 here — and the equipment you list.

·MonCTueCWedSThuCFriCSatCSun
  • SStrength
  • CCardio
  • Rest
DayModalitySession
MonRestRest or mobility
TueCEasy trail run 45–70 min, walk the steep bits
WedCUphill intervals: 5 × 4 min hard climbing, jog/walk down
ThuSSplit squats, step-downs, calf raises, eccentric quad work — heavy, low volume
FriCEasy run or cross-training 40 min
SatCLong run with vertical gain, at effort, fuelling rehearsed
SunCEasy hike or recovery 60 min

S = strength · C = cardio · K = calisthenics. The order is the point: hard days are kept apart and the long session gets the clean slot.

How it adapts when a phase ends

Between phases phase.fitness reads the activities from your watch — duration, elevation gain, heart rate — and the sessions you skipped. If the long runs came in short of the planned duration, the peak's rehearsals are scaled to what you have actually covered rather than to the race; if the uphill intervals were run under effort, the next block's targets move. The strength log tells the plan whether the eccentric work landed or was skipped, which changes how much descending exposure the next phase dares to prescribe.

What the AI does, and what it deliberately does not.

Where the sessions go

phase.fitness plans; you train in the app or on the watch you already use, and the completed session comes back. For this program:

Appphase.fitness sendsComes back
GarminStrength and cardio sessions, on the watchFinished activities, matched to the plan
Intervals.icuCardio sessions, intervals and zones intactCompleted sessions, HRV, CTL and ATL
StravaThe sessions you finish in phase.fitness, when you post themNothing — phase.fitness doesn't import from it
HevyStrength routines: sets, reps, load, RPELogged workouts, with the sets you did

What travels where, per modality and per app.

What phase.fitness does not do here

phase.fitness prescribes the descending and power-hiking sessions by duration and effort; it does not know your course or the trail under your feet, and it will not plan back-to-back long days more than occasionally, because the document it reads calls them a reliable way to overreach.

The evidence

The documents this page is built from

These are the knowledge-base documents the phase.fitness generator reads for this case. The phases, bands and weekly numbers above are transcribed from them.

Frequently asked questions

Does phase.fitness plan by vertical gain?

The trail-running document phase.fitness reads treats vertical gain as the load metric that matters, and the plan prescribes uphill intervals and long sessions with climbing. The sessions themselves are written by duration and effort; the elevation comes back from your watch and is read when the phase ends.

How does the plan train descents?

phase.fitness trains descents with one dedicated descending session a week from the build phase on, progressed by duration first, then gradient, then speed, and with eccentric quadriceps work in the gym. Descending exposure stops in the final two weeks because the soreness it produces is delayed.

Is this suitable for a 50K or a 100K?

The structure is the same; the long sessions scale to 60–75% of expected race duration for events up to marathon distance and to a smaller proportion for ultras, where a full rehearsal is impractical. phase.fitness sets the block length from your event date and current weekly minutes.

The only app that plans strength, cardio and calisthenics together

For a trail runner the calisthenics day is single-leg control and trunk endurance — pistol-squat progressions and long holds — the stability that uneven ground asks for every step.

Right now, phase.fitness is the only training app that writes strength, cardio and calisthenics into one periodized program — same calendar, same phases, same recovery budget.

You choose the mix. A calisthenics-only plan, a cardio-only block, strength plus cardio, or all three: the phases, the end-of-phase analysis and the sync work the same way with one modality or three.

Why calisthenics is in the plan

Bodyweight skill work is strength training in a different shape. Straight-arm work, levers and handstands build scapular control, tendon capacity and relative strength that barbell and machine work leave untouched, and they transfer because they are closed-chain, whole-body patterns. Treated as a modality rather than a warm-up, they get sets, holds and progressions like a squat does.

No exercise catalogue on the market contains a tuck front lever, so those sessions run in the phase.fitness built-in player; strength goes to Hevy, Liftosaur or a Garmin watch, cardio to Garmin and Intervals.icu. How the skill work is programmed.

Build this program for your week

Free to start, no card. The first phase is yours to keep whatever you decide.

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