Ultra and trail coaching, built on physics.

Model the race. Measure the athlete. Close the gap.

Sigwren is the coaching platform for ultra and trail. It decodes the race your athlete is actually running, measures where they are today, and builds the training that gets them to the start line ready.

No card required. Full platform access. Bring your own athletes or test with ours.

Sigwren rehearsing the SkyRun course: elevation profile, satellite route with checkpoints, a course-modelled finish prediction marked still learning, hourly fuel targets with a coach override, and the first segment's climb, pace and leg time.
Rehearsing SkyRun — the course modelled, the splits predicted, the fuel set.

How Sigwren works

Sigwren's difficulty and demands panel for UTMB — distance, vertical gain, technical terrain, night hours and altitude each scored out of five, with the coach's judgement recorded alongside.
The race, decoded: difficulty and demand scored per dimension.

Model the race

Every climb, every descent, every kilometre likely to be run in the dark. Heat windows, technical sections, cutoff pressure by segment. Sigwren turns a GPX file into a full race demand profile so you know exactly what your athlete is preparing for.

Capability trends over a season — critical speed and critical power plotted with their own history, each carrying its measured range.
The athlete, measured: capability trends with their curves.

Measure the athlete

Sigwren combines a full athlete assessment — movement screen, running form, metabolic profile, and trail-specific capability tests for climbing, descending, and technical running — with continuous data from their watch. Eccentric load from descents is modelled and carried forward into recovery and race prediction. Every number has an error band. Every capability is testable. No black-box scores. No vibes.

A training phase in the plan — why this phase exists, the weekly targets it sets, and the zones each session runs in.
The gap, closed: the phase, its purpose, and the week's targets.

Close the gap

The training plan exists to move the athlete's profile closer to the race's demands by race day. Every session has a purpose. Every week narrows the gap. Sigwren does the reasoning so you can do the coaching.

A coach points at a ridge on a large relief model of the escarpment while four trail runners in kit lean in to study the terrain.
Course briefing on the escarpment relief model, before the run.

Coaches have always modelled the race.

A finger on a ridge, and a group that now knows where the day gets hard. Sigwren does the same thing from a GPX file — every climb, every descent, every kilometre likely to be run in the dark — and then keeps doing it for every athlete, every week, without anyone having to be standing at the table.

Scientific foundation and integrations

Built on peer-reviewed physiological models. Minetti gradient cost, Mader metabolic solver, Jeukendrup fuelling, Morton critical power, Cox injury hazard, Foster monotony and strain. Every prediction ships with its error band.

  • Garmin
  • Suunto
  • Polar
  • WHOOP
  • Oura
  • Strava
  • TrainingPeaks