Abstract
Abstract
How increased ventilatory drive shapes the temporal evolution and multidimensional experience of exertional dyspnoea remains incompletely understood. This study examined whether experimentally increasing ventilatory drive via dead-space loading (DSL) alters dyspnoea during constant-load exercise. Nine healthy adults (7 male;
V̇
O
2peak
100 ± 16% predicted) performed constant-load cycle ergometry to task failure at 50%Δ between the gas-exchange threshold and
V̇
O
2peak
under control (CTRL) and DSL (15% vital capacity) conditions in a randomised crossover design. Dyspnoea intensity, dyspnoea unpleasantness, and leg discomfort were assessed using the Borg CR10 scale, and sensory-perceptual and affective-emotional dimensions using the Multidimensional Dyspnoea Profile. Compared with CTRL, DSL increased end-tidal CO
2
, minute ventilation, tidal volume, and inspiratory pressures without altering cardiometabolic responses, and reduced time to task failure (10.0 ± 2.3 vs. 13.8 ± 4.6 min;
p
= .012). Dyspnoea intensity rose more rapidly during DSL, but was similar at task failure, whereas dyspnoea unpleasantness was consistently higher without a distinct temporal divergence. Leg discomfort and dyspnoea descriptor frequencies did not differ between conditions. Post-exercise multidimensional profiling revealed greater breathing unpleasantness (
p
= .008), immediate perception scores (
p
= .036), respiratory work/effort (
p
= .040), and air hunger (
p
= .027), with no differences in emotional response scores. Greater iso-time increases in dyspnoea intensity and unpleasantness were associated with shorter time to task failure (
r
= − .82 to − 0.88;
p
≤ .007). These findings suggest that increased ventilatory drive accelerates dyspnoea development and preferentially augments sensory-perceptual characteristics of dyspnoea, contributing to earlier task failure despite similar end-exercise symptom intensity.