Ventilatory pattern restructuration under VST-dominant intervention outside the WorldTour cohort: two contrasting trajectories and the role of intermediate supervisory monitoring

Background. The Ventilatory Strategies & Training (VST) protocol has been developed and validated in a cohort of professional cyclists (Ricci & Bouverot, 2025, DOI 10.5281/zenodo.16645438), with documented mechanical gains of +30 W at the first ventilatory threshold (VT1), +38 W at the second ventilatory threshold (VT2), and +24 W at VO₂max over 48 weeks. The directional reproducibility of the VST ventilatory signature (Tv ↑, Rf ↓, VE-efficiency coupling) outside the absolute elite cohort remains poorly documented, as do the consequences of unsupervised application. Objective. To document the longitudinal trajectory of the ventilatory pattern in two athletes followed outside the WorldTour context, in contrasting intervention settings, and to examine the role of intermediate supervisory monitoring as a design variable for VST interventions. Methods. Retrospective observational case series n = 2, three complete dynamic physiological profilings per athlete (ramp test stages of 2 min / 25 W, VO₂ Master Pro, Moxy NIRS): TRI01 professional long-distance triathlete (33 years, 74-75 kg), VST-dominant ventilatory intervention (isocapnic training from December 2024, resistive inspiratory muscle training — PowerBreathe K5 — from March 2025) with four presential intermediate supervisory monitorings; EC01 elite amateur cyclist (30 years, 72 → 69 kg), multimodal intervention including isocapnic training but without intermediate monitoring until February 2025, followed by re-targeting of isocapnic exercise execution and introduction of a variable-resistance inspiratory training device (PowerBreathe K3). Results. TRI01 exhibits a progressive and coherent restructuration of the ventilatory pattern across the three profilings: at iso-power ~290 W, Rf decreases from 36.49 to 17.21 cycles·min⁻¹ (−52.8 %), Tv increases from 2.52 to 4.53 L (+79.8 %), and VE remains controlled (−14.4 %) between baseline and 12 months. EC01 shows in February 2025 a calibration drift characterized by a focus on Rf reduction without maintenance of tidal volume at rising intensity: at 322 W, Tv decreases to 3.24 L from 3.49 L at the previous stage, VE collapses to 91.61 L·min⁻¹ (vs. ~135 L·min⁻¹ expected at this intensity). After isocapnic re-targeting and introduction of structured inspiratory training, the June 2025 profiling shows at iso-power ~284 W a Tv maintained at 4.19 L and a VE of 92.20 L·min⁻¹ consistent with metabolic demand, accompanied by an improvement in FeO₂ (15.58 % vs. 16.99 % in February).Conclusion. The VST directional signature (Tv ↑, Rf ↓, VE-constrained) appears reproducible outside the WorldTour cohort. The qualitative differential between the two trajectories — optimized signature in TRI01, documented intermediate drift then corrected in EC01 — is compatible with a determining role of intermediate supervisory monitoring in the quality of restructuration. This differential is furthermore convergent with the reference case documented by Ricci & Bouverot (2025, DOI 10.5281/zenodo.17657685) on non-individualized ventilatory manipulation drift. It cannot be excluded that other individual factors contributed to the observed differential; a prospective design would remain necessary to establish robust causality.