PURPOSE: The aim of this project was to study the impact of pedal rate on breakpoints in muscle oxygenation (deoxy[Hb + Mb] and total[Hb + Mb]) and activation (iEMG and MPF) at high intensities during ramp exercise. METHODS: Twelve physically active students performed incremental ramp exercises at 60 rpm, starting either at 50 or 80 W (i.e., 60rpm50 and 60rpm80), and at 100 rpm, starting at 50 W (100rpm50). Pulmonary VO2, muscle activation (iEMG and MPF) and oxygenation were recorded with EMG and NIRS, respectively. IEMG, MPF, deoxy[Hb + Mb] and total[Hb + Mb] were expressed as functions of work rate (WR) and pulmonary VO2 (%VO2peak) and analyzed with double-linear models. RESULTS: The breakpoints (BP) of iEMG, MPF, total[Hb + Mb] and deoxy[Hb + Mb] in %VO2peak did not differ among the pedal rate conditions (P > 0.05), whereas the BPs in WR were significantly lower in 100rpm50 compared to 60rpm50 and 60rpm80 (P < 0.01). Across the pedal rate conditions the BP (in %VO2peak) of total[Hb + Mb] (82.7 ± 1.5 %VO2peak) was significantly lower (P < 0.01) compared to the BP in iEMG (84.3 ± 1.7 %VO2peak) and MPF (84.2 ± 1.6 %VO2peak), whereas the BP in deoxy[Hb + Mb] (87.4 ± 1.4 %VO2peak) and respiratory compensation point (89.9 ± 1.8 %VO2peak) were significantly higher (P < 0.01) compared to the BP in total[Hb + Mb], iEMG and MPF. Additionally, the BPs in iEMG, MPF, total[Hb + Mb] and deoxy[Hb + Mb], and the RCP were highly correlated (r > 0.90; P < 0.001). CONCLUSIONS: The present study showed that muscle activation and oxygenation at high intensities during incremental exercise are related to pulmonary VO2 rather than external WR, with a close interrelationship between that muscle activation, oxygenation and pulmonary VO2.
PURPOSE: The aim of this project was to study the impact of pedal rate on breakpoints in muscle oxygenation (deoxy[Hb + Mb] and total[Hb + Mb]) and activation (iEMG and MPF) at high intensities during ramp exercise. METHODS: Twelve physically active students performed incremental ramp exercises at 60 rpm, starting either at 50 or 80 W (i.e., 60rpm50 and 60rpm80), and at 100 rpm, starting at 50 W (100rpm50). Pulmonary VO2, muscle activation (iEMG and MPF) and oxygenation were recorded with EMG and NIRS, respectively. IEMG, MPF, deoxy[Hb + Mb] and total[Hb + Mb] were expressed as functions of work rate (WR) and pulmonary VO2 (%VO2peak) and analyzed with double-linear models. RESULTS: The breakpoints (BP) of iEMG, MPF, total[Hb + Mb] and deoxy[Hb + Mb] in %VO2peak did not differ among the pedal rate conditions (P > 0.05), whereas the BPs in WR were significantly lower in 100rpm50 compared to 60rpm50 and 60rpm80 (P < 0.01). Across the pedal rate conditions the BP (in %VO2peak) of total[Hb + Mb] (82.7 ± 1.5 %VO2peak) was significantly lower (P < 0.01) compared to the BP in iEMG (84.3 ± 1.7 %VO2peak) and MPF (84.2 ± 1.6 %VO2peak), whereas the BP in deoxy[Hb + Mb] (87.4 ± 1.4 %VO2peak) and respiratory compensation point (89.9 ± 1.8 %VO2peak) were significantly higher (P < 0.01) compared to the BP in total[Hb + Mb], iEMG and MPF. Additionally, the BPs in iEMG, MPF, total[Hb + Mb] and deoxy[Hb + Mb], and the RCP were highly correlated (r > 0.90; P < 0.001). CONCLUSIONS: The present study showed that muscle activation and oxygenation at high intensities during incremental exercise are related to pulmonary VO2 rather than external WR, with a close interrelationship between that muscle activation, oxygenation and pulmonary VO2.
Authors: Goutham Ganesan; Szu-Yun Leu; Albert Cerussi; Bruce Tromberg; Dan M Cooper; Pietro Galassetti Journal: Pediatr Exerc Sci Date: 2015-10-09 Impact factor: 2.333
Authors: Stephan van der Zwaard; Richard T Jaspers; Ilse J Blokland; Chantal Achterberg; Jurrian M Visser; Anne R den Uil; Mathijs J Hofmijster; Koen Levels; Dionne A Noordhof; Arnold de Haan; Jos J de Koning; Willem J van der Laarse; Cornelis J de Ruiter Journal: PLoS One Date: 2016-09-15 Impact factor: 3.240
Authors: Robert T Mankowski; Victor M Niemeijer; Jasper P Jansen; Lotte Spraakman; Henk J Stam; Stephan F E Praet Journal: J Exerc Sci Fit Date: 2017-07-19 Impact factor: 3.103