Affordable Access

Access to the full text

The impact of pedal rate on muscle oxygenation, muscle activation and whole-body VO2 during ramp exercise in healthy subjects

  • Boone, Jan1, 2
  • Barstow, Thomas J.3
  • Celie, Bert1
  • Prieur, Fabrice4
  • Bourgois, Jan1, 2
  • 1 Ghent University, Department of Movement and Sport Sciences, Watersportlaan 2, Ghent, 9000, Belgium , Ghent (Belgium)
  • 2 Ghent University Hospital, Center of Sports Medicine, Ghent, Belgium , Ghent (Belgium)
  • 3 Kansas State University, Kansas, USA , Kansas (United States)
  • 4 Université Paris Sud-Université d’Orléans, Laboratoire CIAMS, Equipe MHAPS, Orléans, France , Orléans (France)
Published Article
European Journal of Applied Physiology and Occupational Physiology
Publication Date
Sep 10, 2014
DOI: 10.1007/s00421-014-2991-x
Springer Nature


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.MethodsTwelve 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.ResultsThe 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).ConclusionsThe 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.

Report this publication


Seen <100 times