THE INTERRELATIONSHIP BETWEEN MUSCLE OXYGENATION, MUSCLE ACTIVATION AND PULMONARY VO2 TO INCREMENTAL RAMP EXERCISE: INFLUENCE OF AEROBIC FITNESS

We investigated whether muscle and ventilatory responses to incremental ramp exercise would be influenced by aerobic fitness status by means of a cross-sectional study with a large subject population. Sixty-four male students (age: 21.2±3.2years) with a heterogeneous VO2peak (51.9±6.3ml.min-1.kg-1, range 39.7-66.2ml.min-1.kg-1) performed an incremental ramp cycle test (20-35Watt.min-1) to exhaustion. Breath-by-breath gas exchange was recorded, and muscle activation and oxygenation were measured with surface electromyography (sEMG) and near-infrared spectroscopy (NIRS), respectively. The integrated EMG (iEMG), Mean Power Frequency (MPF), deoxy[Hb+Mb] and total[Hb+Mb] responses were set out as functions of work rate (W) and fitted with a double linear function. The respiratory compensation point (RCP) was compared and correlated to the breakpoints (BPs) (as %VO2peak) in muscle activation and oxygenation. The BP in total[Hb+Mb] (83.2±3.0%VO2peak) preceded (PThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author