Vert tracking for trail runners, done honestly

Trail runners count vert the way road runners count mileage. Total meters climbed per run, per week, per season: it is the one number that captures what a mountain block actually asked of your legs, and for climb-heavy races it predicts readiness better than distance ever will. A 60 km week with 800 m of vert and a 60 km week with 3,000 m are different sports.

But vert is also the most casually mismeasured number in the sport. Before you build training decisions on it, it is worth knowing where the number comes from and how to keep it honest.

Where your vert number actually comes from

Devices measure elevation in two fundamentally different ways. Watches with a barometric altimeter read air pressure changes as you climb, which resolves small elevation changes well but drifts when the weather moves, since a passing front changes pressure without you climbing anything. Devices without a barometer either use raw GPS altitude, which is far noisier than GPS position, or have their track cross-referenced against an elevation database after the run.

Platforms then apply their own corrections. Strava, for example, documents that it keeps barometric data from devices it recognizes as having an altimeter, and computes elevation from a basemap for everything else. This is why the same run can show 840 m on your watch, 780 m on one platform and 900 m on another, and why your training partner's number rarely matches yours; Strava has a support page dedicated to exactly that complaint.

There is a subtler distortion too: total ascent is the sum of many small climbs, so how aggressively a device smooths its elevation trace changes the total. Count every one-meter stutter in a noisy signal and a rolling trail gains imaginary vert; smooth too hard and real short climbs vanish.

The rule: one source, applied consistently

For training purposes you do not need the true number, which is genuinely hard to define on rolling ground. You need a consistent one. Vert is a relative instrument: this week against last week, this year's July against last year's. That leads to a few practical rules:

• Pick one device and one platform and stay with them. A consistent bias subtracts out of every comparison. Switching sources mid-season quietly breaks your history.
• Never compare your vert to someone else's. Different hardware, different smoothing, different truth. Compare runners by the climbs they can hold, not by their elevation totals.
• Treat round numbers as approximate. "About 1,900 m this week" is an honest reading of the instrument. "1,912 m" is not.

Turning vert from a trophy into a signal

Weekly vert is most useful when you treat it like mileage: a load to build deliberately, not a score to admire.

• Know your baseline. Average your last several normal weeks. Most runners are surprised in both directions.
• Ramp it like mileage. Climbing load stresses calves, achilles and quads (the descending that comes with the vert is the quieter half of the cost). Sharp jumps in vert deserve the same respect as sharp jumps in distance.
• Watch vert pace, not just volume. Meters climbed per hour on a sustained climb, VAM in cycling language, is a fitness signal in a way raw weekly vert is not. Our free GAP and climb calculator reads climb rate off any climb you enter, alongside grade and grade-adjusted pace.
• Anchor the number to real hills. The most meaningful vert is vert you can name: four repeats of the water tower climb is a fact about your legs; 214 m is just its shadow. Progress lives in the named climb's history, a case we make in how to track hill repeats properly.

Counting what the counting is for

A vert total is a proxy. What you actually want to know is whether the climbing you did is making you a stronger climber, and that answer lives one level deeper than the weekly sum: in the same hills, timed the same way, compared across the season. That is the part Trailbuddy is being built to automate, keeping a history per climb with conditions on the record, while the vert total takes care of itself. In the meantime: one source, consistent habits, and a healthy suspicion of any elevation number quoted to the meter.