If you are into trail running, mountain biking or hiking, you have almost certainly downloaded more than one .GPX file from Wikiloc, Komoot, Strava or the official site of your next race. But opening it and seeing a blue line on a map is not analysis. In this guide you will learn how to pull genuinely useful information out of any GPX so you can prepare better for your outings and races.
What exactly is a GPX file?
GPX stands for GPS Exchange Format. It is a standard XML format that stores coordinates (latitude, longitude), altitude and, optionally, timestamps and heart rate. It is the most universal format there is: Garmin, Suunto, COROS, Polar, Wahoo and almost every outdoor app support it.
A GPX is not an image or a map. It is a list of points. The quality of your analysis depends on how many points it holds, how many metres apart they were recorded, and whether they include barometric altitude or GPS altitude alone.
The 5 metrics you should ALWAYS look at
1. Real distance (not the one on the entry form)
A race's official distance and the real distance measured by the GPX can differ by as much as 5-8%. That comes down to bends that were never counted, GPS errors under tree cover or last-minute changes to the route. Always trust the GPX, not the poster.
2. Total elevation gain (D+)
This is the metric that causes the most confusion. Elevation gain depends on the smoothing algorithm each platform uses. Strava, Garmin Connect and Komoot can all give you different figures for the same file. The gap can be 10-20%.
At TrackLAB we use an algorithm based on the UTMB and ITRA method, calibrated against real times from benchmark races. That means the elevation gain we show matches the figure the organisers use to award ITRA points.
3. Elevation profile
The altitude-versus-distance chart is where the truth about a route hides. Learn to read it:
- Gradients above 15%: you will have to walk, even as a runner.
- Gradients of 8-15%: a jog or a fast hike on trail, small chainring on the bike.
- Gradients of 3-8%: a sustainable race pace.
- Gradients below 3%: near enough flat, so use it to recover.
4. Key climbs
A key climb is a continuous stretch with significant elevation gain (usually more than 100 m). Spotting them lets you plan where to spend energy and where to recover. In long races, bad pacing on the first big climb mortgages the rest of your day.
5. Personalised estimated time
The most common mistake is using your flat pace to estimate the time for a mountain route. It does not work like that. Your real time depends on your weight, your training level and the fatigue that elevation gain builds up.
TrackLAB works out your estimated time using validated physiological equations (Minetti, Tobler), adjusted to your level: beginner, amateur, advanced or professional.
Advanced metrics that separate a casual user from an expert
Vertical ascent speed (VAM)
Metres of elevation gain climbed per hour. It is the most honest indicator of your real level. An amateur trail runner climbs at between 600 and 900 m/h. An advanced one, 1,000-1,400 m/h. UTMB professionals sit around 1,500-1,800 m/h on long climbs.
Equivalent effort
This converts any route with elevation into its flat equivalent. It lets you compare like with like: a 25 km route with 1,500 m+ works out at roughly 40-45 km on the flat in terms of metabolic load.
Heart rate zones (if your GPX includes them)
If you record with a heart rate monitor, your GPX may contain HR data. That unlocks zone analysis (recovery, endurance, threshold, VO2max) and the ability to spot fatigue through cardiac drift.
How to analyse your GPX in TrackLAB in 3 minutes
- Upload your file: drag the GPX or FIT into the analyser. You can also paste a Komoot or Wikiloc URL.
- Check the basic metrics: distance, elevation gain, maximum altitude, estimated time.
- Explore the elevation profile: use the interactive chart to pick out the key climbs.
- Turn on TrackLAB RouteLab (PRO): get automatic analysis of segments, gradients and critical points.
- Turn on TrackLAB BioCenter (PRO): see your estimated physiological effort, HR zones and fatigue prediction.
Common mistakes when reading a GPX
- Trusting the elevation gain from a single service: cross-check it across two or three platforms.
- Ignoring data quality: a GPX with one point every 50 m is no use for fine-grained analysis.
- Not looking at the profile before you set off: knowing where the big climbs are changes your strategy.
- Underestimating elevation loss: dropping 1,500 m destroys your quads. It counts every bit as much as climbing.
Conclusion
Analysing a GPX is not complicated, but it does mean understanding what you are looking at. With the five basic metrics (distance, elevation gain, profile, key climbs, estimated time) you already have 80% of the useful information. The advanced metrics are what separate finishing a race from mastering it.
Ready to analyse your first GPX? Get started for free at tracklab.app/analyzer — no card, no strings attached.