Threshold : the upper sustainable limit
LoadThe maximum intensity sustainable for about 1 hour (FTP on bike, CSS in swim).
At threshold, lactic acid builds up in the muscle faster than you can clear it. It's the line between hard-but-sustainable and effort that drops you within minutes. Threshold training pushes that line higher.
In TriPaced:
TriPaced prescribes threshold work as short intervals (e.g., 4×8 min at threshold, 3 min recovery) during build blocks. Dose is calibrated to protect weekly recovery.