Abstract des Autors

This study compared breathing frequency (fB) during a ventilation threshold (VT) test with fB during a simulated 40 km time trial (40TT) to assess whether fB can be used to monitor exercise intensity. Twenty-six male cyclists performed an incremental VT ergometer test and a simulated 40TT on a set of wind-loaded rollers. During the 40TT, expired gas was collected for 3 min using open circuit spirometry at 10 km intervals. A significant correlation was found between the fB threshold (VTf) and the gas exchange VT (VTg). No differences were found in VO2 at the VTf vs. mean VO2 during the simulated 40TT. However, when fB in br/min calculated from the VT test (32.5 br/min), was compared with fB during the 40TT (45.6 br/min), there was a significant difference. Ventilation, heart rate and the respiratory exchange ration were all significantly higher during the 40TT. Although a significant relationship was found between the VT test and the 40TT for VTf measured in l/min of VO2, fB in br/min obtained from the incremental tests should not be used to identify exercise training intensity. These data suggest that during competition, trained athletes exercise at a higher fB than that determined when being tested, implying that fB in br/min may not be a valid measurement of exercise intensity. Verf.-Referat