The session is the stimulus. The adaptation happens in the rest that follows it. This is the principle most amateur cyclists treat as theoretical and then ignore in practice — they ride harder on Tuesday because Monday's session 'felt easy', and the cumulative recovery debt eats every gain the training was supposed to produce. Specific adaptations match specific stimuli: zone 2 builds mitochondria and capillary density; threshold builds lactate clearance; VO2max work raises the aerobic ceiling; heavy strength work preserves type II fibres and bone density. Each requires its own dose, its own recovery, and its own consistency over weeks. The Roadman position, repeated across hundreds of conversations with World Tour coaches: amateur cyclists do not have a training problem; they have a recovery problem. Train less hard, eat the carbs the work demands, sleep enough — and the adaptation will land.