Power output at the moderate-to-heavy intensity transition decreases in a non-linear fashion during prolonged exercise

• DOI: 10.1007/s00421-024-05440-3
• Publication Date: 2024-03-14T15:05:26Z
• Authors: Gabriele Gallo; Emanuela Luisa Fa...; Piero Ruggeri; Luca Filipas; Roberto Codella; Daniel J. Plews; Ed Maunder
• Keywords: Intensity; Ventilatory threshold; Exercise intensity; Cycling; Human physiology; Exercise physiology; Sports medicine

Abstract Purpose The aims of this study were to: (i) describe the time course decrease in power output at moderate-to-heavy intensity transition during prolonged exercise; (ii) investigate association between durability and exercise capacity; (iii) explore physiological correlates transition. Methods Twelve trained cyclists (age: 40 ± 8 y, $$\dot{\text{V}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mtext>V</mml:mtext> <mml:mo>˙</mml:mo> </mml:mover> </mml:math> O 2 peak: 52.3 5.2 mL·min −1 ·kg ) performed an exhaustive cycling protocol involving alternating incremental tests to determine via first ventilatory threshold (VT 1 ), 30-min bouts 90% previously estimated VT rested state. individual was modelled using linear second-order polynomial functions, a 5% (Δ5%VT best-fitting model. Results Power decreased according function 11 12 participants. Time-to-task failure (234 66 min) correlated with Δ5%VT (139 78 min, r s = 0.676, p 0.016), these strongly absolute relative rates fat oxidation specific intensities measured test Conclusions These data: identify non-linear decreases support importance suggest is related rates.