VELOARCHITECT

Zone 2 is the load-bearing layer. The Athlete’s sub-threshold ceiling extends across 6–12 week Z2 blocks; Mechanical Efficiency moves consistently at lower cardiac cost. Veloarchitect dispatches this template as the default weekly volume builder. The Athlete who skips Z2 collapses the sub-threshold ceiling and bonks at kilometer 110 of a gran fondo regardless of FTP.

Zone 2 is the longest-arc work in the system. Single rides are noisy because heat, fuel, hydration, and pacing bias the W/bpm ratio; tracked across months, the ratio is the largest signal the system reads. The 90-minute template is the minimum dose — Veloarchitect Athletes targeting gran fondos, centuries, or stage races receive 2–4 hour Z2 templates in addition.

Protocols: Protocol 1 — Zone Endurance; Protocol 8 — Fueling Window

Worked Example — 8-week Z2 base block

Athlete: 41y/o, 254W FTP, 1.43 W/bpm. 8-week block: 3 weekly Z2 endurance (60→90→120 min progression) + 1 weekly Threshold Sustain + 1 weekly Recovery Spin. Mechanical Efficiency: 1.43 → 1.58 W/bpm. Sub-threshold ceiling: 3:15 → 5:45. FTP test on week 9: +9W (lower than a Sweet-Spot-heavy block would produce, but the Metabolic engine is rebuilt for the long haul).