Turn trail distance and elevation into a practical starting point.

Research basis

• Equations and numerical ranges: HRmax from Nes et al. (2013) and Gulati et al. (2010); aerobic-capacity factors from Uth et al. (2004) and Uth (2005); distance-scaling form from Riegel (1981); course-energy polynomial from Minetti et al. (2002); carbohydrate ranges from Jeukendrup (2014) and Burke et al. (2011); the 60/90/120 g/h targets and glucose:fructose blend ratios from Podlogar & Wallis (2022); gut-training basis from Jeukendrup (2017); walking and running speed–oxygen-cost conversions from the metabolic equations in ACSM's Guidelines for Exercise Testing and Prescription, applied through the VO₂-reserve method of Swain & Leutholtz (1997).
• Effort framework and profile context: Garber et al. (2011), Rodríguez-Medina et al. (2025) and Fornasiero et al. (2018).
• Conventions and product heuristics: Montagne Trekking documents the full hiking-derived kilomètre-effort convention as distance + D⁺/100 + D⁻/400. Montagne Trekking: kilomètre-effort. The usual rationale equates the time for 1 flat kilometre with 100 m ascent or 400 m descent. Same-duration explanation. ITRA's trail-race classification documents the ascent term but omits descent. ITRA race evaluation. Applying the full hiking convention to trail moving time remains a product heuristic.