Ventilatory mechanics, frequency-dependent discriminating muscles and diaphragm-thorax co-activation: towards an integrative framework for endurance performance

The ventilatory system has long remained peripheral to endurance performance models, on the grounds that it does not limit VO₂max under normoxic conditions. This narrative review proposes an integrative framework articulating three complementary dimensions: the graduation of discriminating ventilatory muscles according to respiratory frequency domain, the mechanisms of the ventilatory rebound effect, and the mechanics of diaphragm-thorax co-activation. The text explicitly distinguishes established data, mechanistically plausible interpretations, and original proposals requiring experimental validation. Alternative determinants — locomotor-ventilatory coupling, descending neural control — are also discussed. The ensemble suggests that ventilatory optimisation in performance requires both an intensity-adapted strategy and specific muscular capacity to sustain it — two dimensions whose integrated interaction remains to be documented experimentally. This framework provides testable hypotheses and may help guide more targeted ventilatory interventions in endurance performance.