The impact of inspiratory threshold loading on constant load exercise has been examined using absolute exercise intensities (Carra, J. et al. Journal of Applied Physiology. 2003; 94: 2448-2455). However, breathing load may alter the work-rates at which V̇O2peak and gas exchange threshold (GET) occur. Therefore, the aim of this study was to determine the effect of threshold loading on the response to ramp exercise. Twelve active males took part in this study. At separate visits (>48 hrs.) subjects performed maximal ramp cycle tests to determine V̇O2peak and GET with either no inspiratory resistance or threshold loads of 15 and 30 cmH2O. Breath-by-breath V̇O2 data was modelled using a bi-exponential function. The effect of inspiratory load on the V̇O2 response to ramp exercise was determined with one way analysis of variance and post-hoc linear trend analysis. During ramp exercise there were significant linear trends in GET (P=0.041) and peak power (P=0.002). There was no effect on V̇O2peak (P=0.719). This study has shown that the work-rate at GET decreases as threshold-load increases. Therefore, studies investigating constant load exercise should consider the use of intensities relative to GET.
|Title of host publication||European Respiratory Journal|
|Number of pages||1|
|Publication status||Published - 2014|