VELOARCHITECT

Threshold Sustain is the protocol that owns the lactate boundary work — Sweet Spot, classic threshold blocks, and over-unders all belong here. Standard 88% prescriptions fix duration at 20 minutes and intensity at 88% FTP. Veloarchitect dispatches Threshold Sustain calibrated to the Athlete’s drift tolerance: the system reads per-interval ZWO→FIT Delta across the 100-day record and assigns the block whose drift band matches the Athlete’s actual floor — an Athlete with a 6-W drift on a 20-minute Sweet Spot block receives 2×10 at 92% FTP, not 2×20 at 88%. The protocol respects the Athlete's lactate-clearance capacity as a longitudinal marker, not a single-session ceiling.

Protocols: Protocol 10 — Adaptive Workout; Protocol 2 — VO₂max Repeats

The metric traverses the closed loop: Intent is the .zwo prescription the system computed against the Athlete’s True Normal. Telemetry is the .fit recording of the executed session. Adaptation is the longitudinal movement of the metric itself, logged against the True Normal and feeding back into the next day’s prescription via Protocol 10 (Adaptive Workout).