The Engine

Vertical Trail Labs is not a blog or a CMS. It's a data intelligence engine whose final output is this static website: the site never calculates anything, it only shows what the Engine already computed from each race's official GPX and checkpoint split times.

🧗 VPI — Vertical Power Index

Meters of elevation gain per hour, measured only on strong-climb segments (slope ≥12%). Measures pure climbing efficiency and specific power output on severe vertical gains.

VPI = Σ(elevation gain on segments ≥12%) / Σ(athlete time on those segments)

📉 DMI — Descent Mastery Index

Speed (km/h) on strong-descent segments (slope ≤-12%). Measures technical downhill skill and muscular resilience against heavy eccentric loading.

DMI = Σ(distance on segments ≤-12%) / Σ(athlete time on those segments)

🏆 ER — Endurance Rating

A 0-100 score measuring pacing degradation between the first and second half of the race, measured in effort-kilometers (distance + elevation/100) instead of raw distance.

ER = 100 − (pacing decay % between halves)

Data Flow

Engine (Python) → JSON → Builder (Jinja2) → Static HTML → Cloudflare Pages