For trail and ultra runners

Train for the terrain. Ready for the race.

Pendio turns the organiser's course file into your race: what the terrain will do to you, how to pace and fuel it, and the part you want to train on, on your watch.

Private beta · no spam · just a heads-up when it opens.

Elevation · Three Passes 50 · a made-up course Distance50.3 km Gain↑ 2,757 m Loss↓ 2,757 m Peak2,645 m peak 2,645 m
0 km50.3 km
Hardest climb11.0 km @ +12.2 %
Hardest descent9.5 km @ −16.2 %
See the race course pages

Try it with your race. Drop its GPX here, or click to choose the file. It's read right here in your browser and never uploaded.

Race day

From the organiser's page to the start line.

One file, the organiser's own, carries the whole preparation: from the race's page to your account, the race plan, your watch and a printed pace card.

  1. The race page. Every race course page reads the organiser's GPX with Pendio's engine: the profile, the hardest climb and descent, the terrain, and the effort between the aid stations.
  2. Add to Pendio. One tap puts the course in your Pendio account. Your phone or browser downloads the file from the organiser's own site, and Pendio checks it against the file the page measured; Pendio never republishes it.
  3. The race plan. The organiser's aid stations and cut-offs come with it. Type a target time and each stop gets an arrival time and a cut-off margin, with the carbs and gels for every leg.
  4. Section for your watch. Cut any part of the course, a climb or the leg between two aid stations, into a GPX your watch can follow, with the plan's aid stations on it.
  5. The pace card. One printed page with the splits, the cut-off margins and the gels, for your pocket, your bottle or your crew.

See the race course pages · or bring any GPX. Below, the plan on a made-up course:

  1. The hardest climb, the hardest descent, and where the climbing sits.

  2. Your target time shared out over the terrain: an arrival time and a cut-off margin at every stop. How it's worked out

  3. Carbs for the whole day, and how many gels to eat on each leg.

  4. The plan on one page, for your pocket, your bottle or your crew.

Elevation · Three Passes 50peak 2,645 m
0 km50.3 km

The hardest climb, the hardest descent, and where the climbing sits.

Hardest climb
Hardest descent
High point
Terrain
Climbing47 % Flat6 % Descending47 %
D+ per 10 km

Training · in the iPhone app

Ready for the terrain.

Your workouts are read the way the course is, on your iPhone, so your training and your race are measured on the same ground. Most apps treat a flat 10K and a 1,000 m grind the same; Pendio doesn't.

A flat 10K
10.0 km · ↑ 40 m As Pendio counts it10.0 km
A 1,000 m grind · 5 km up, 5 km down
10.0 km · ↑ 1,000 m As Pendio counts it20.1 km

Same distance on the map. Pendio weighs every stretch by how much its grade slows you down, so the grind counts as 20.1 km of flat running.

  • Ready for this course? Your last 8, 12 or 16 weeks held against the race: volume, longest effort, weekly climbing, and how well your terrain matches its climbs and descents. A heuristic, not a verdict, and it says so.
  • Section for your watch. Pick a climb, a leg between two aid stations or any kilometre range, reverse it or make it an out-and-back, and take a GPX your watch can follow, with the plan's aid stations on it.
  • Descents count. Quads keep the bill for the downhill that heart rate forgets, so every descent is a load of its own, next to your training load.
  • Climbs, found and kept. The same climb is recognised every time you run it, with no segments to set up, and its efforts line up.

How readiness is scored

Where the course asks more

Descent Load Index

What it measuresEccentric quad load from descending — the soreness that ends mountain races. Segments steeper than −3% count distance × (grade ÷ 10)²; 1 km at −10% ≈ 1.0.

The chartThe bars are your DLI per ISO week over the last 12 or 26 completed weeks; the dashed guide is your chronic level today, the 28-day sum ÷ 4. Tap a week to read it against the chronic level it had then; tap it again to go back to last week.

Building itLike all load, downhill tolerance builds progressively — watch for big week-to-week jumps before a race with long descents. The week rail inverts the 0.8–1.3 acute:chronic convention into this week's DLI budget; it resets each Monday.

Same as the gaugeIt's the same series as the DLI gauge in Load: ratio there, trajectory here.

Descent load
Readiness

/ 100

A heuristic, not a verdict — it can't see injury history, heat acclimation or years of base.

Example cards from the iPhone app, for a fictional athlete training for Three Passes 50.

Section
0 km

Between waypoints

Example cards from the iPhone app, for a fictional athlete training for Three Passes 50.

Descent load

Example cards from the iPhone app, for a fictional athlete training for Three Passes 50.

Example cards from the iPhone app, for a fictional athlete training for Three Passes 50.

Join the beta

pendio.app

Plan at your desk. Race with your phone.

Sign in at pendio.app with your email, Google or Apple, with no password. Your season, your courses and their race plans are there on a big screen, and every change reaches your phone.

Season

A, B and C races with a countdown, the A-race taper on a timeline, and a flag when two races sit too close.

Race plan

Place aid stations and cut-offs on the profile, set your target and print the pace card, on a screen big enough for a 100 km course.

In sync with your phone

Races, courses and plans travel both ways. Edits made offline wait and sync when you're back.

Sign in on the web Read the guide

Training analysis stays in the iPhone app. The web never shows your readiness, predictions or training load — your workouts never leave your phone.

Private by design

Your workouts never leave your phone.

Pendio reads your activities from Strava or Apple Health and runs every calculation on your iPhone. Our small server keeps your sign-in (no passwords) and the race plan you type — races, courses, fueling and aid stations — so it's there on the web and on a new phone. Never your workouts.

Strava or Apple Health Analyzed on your iPhone Workouts stay there

Private beta

Be first on the trail.

Pendio is in private beta. Leave your email and we'll let you know the moment it opens up.

Or email hello@pendio.app.

Questions

What kind of athlete is Pendio for?
It's built first for trail and ultra runners — anyone whose races are decided by climbs, descents and fueling. Road runners and cyclists who train on hilly terrain get the same grade-aware analysis; sport is never the thing Pendio colors, the ground is.
Do I need a special watch or device?
No. Pendio reads the activities you already record — through Strava, or from Apple Health on your iPhone. If a workout has GPS and elevation, Pendio analyzes its terrain; without a route it still counts toward your training load.
How does the race analysis work?
Import a route's GPX and Pendio profiles its terrain — hardest climb and descent, how the vertical is distributed — then compares it against your recent training to estimate readiness, and builds a fueling plan from your target time. Every figure is descriptive and attributed; it never invents data it doesn't have.
How are the planned split times calculated?
From your target time and the course, nothing else. Your stops come off the target first; the rest is shared between the legs by how hard each one is — every leg is converted to flat-equivalent kilometres with the grade-adjusted pace model — so you hold one even effort and the climbs simply take longer. Optional fatigue-drift and night factors reshape the splits without moving the finish. The guide walks through an example.
What's the course on this page?
Three Passes 50 is made up for this page: a 50 km loop in the Swiss Alps with three passes, drawn as a GPX and run through Pendio's own analysis, so every number you see is what the app would show. It isn't a real race. Drop your own race's GPX on the card at the top to see it instead.
Can I use Pendio on a computer?
Yes, for race preparation. Sign in at pendio.app/app with your email, Google or Apple to manage your season, import race courses, set your fueling and build race plans with a pace card PDF. Everything syncs with your phone. Training analysis — readiness, load, climbs — stays in the iPhone app, because your workouts never leave your phone.
Where is my data stored?
Your workouts, and everything Pendio computes from them, stay on your iPhone. A small Pendio server keeps what it needs to sign you in and the race plan you type — races, courses, fueling settings and aid stations — so you find them on the web and on a new phone. It never receives your workouts. A GPX you drop on this page is read in your browser and never sent anywhere. See the privacy policy.
How much will it cost?
Pricing isn't set yet. Join the beta and you'll be the first to hear — beta access itself is free.