Detraining : fitness loss when training stops
LoadThe reversal of training adaptations when training is reduced or stops.
Aerobic adaptations (VO2max, FTP, running economy) begin declining in 10-14 days without training, with a measurable 5-10% VO2max drop over 4 weeks. Muscle mass is more resilient (weeks to months). The good news: muscle 'remembers' : after a 4-week break, a trained athlete rebounds in roughly half the time it took to build the initial fitness.
In TriPaced:
In TriPaced, a gap in Strava activity naturally pulls CTL down. If you return after 2+ weeks off, the engine suggests a 'Progressive Return' block at reduced intensity to prevent comeback injury : you'll want to do more than prescribed; resist the urge.