title: Respiratory muscle endurance, oxygen saturation index in vastus lateralis and performance during heavy exercise.
abstract: The purpose of this study was to investigate the relationships between respiratory muscle endurance, tissue oxygen saturation index dynamics of leg muscle (TSI) and the time to exhaustion (TTE) during high intensity exercise. Eleven males performed a respiratory muscle endurance test, a maximal incremental running field test (8 km h(-1)+0.5 km h(-1) each 60s) and a high-intensity constant speed field test at 90% VO2max. The TSI in vastus lateralis was monitored with near-infrared spectroscopy. The TSI remained steady between 20 and 80% of TTE. Between 80 and 100% of TTE (7.5 ± 6.1%, p<0.05), a significant drop in TSI concomitant with a minute ventilation increase (16 ± 10 l min(-1)) was observed. Moreover, the increase of ventilation was correlated to the drop in TSI (r=0.70, p<0.05). Additionally, respiratory muscle endurance was significantly correlated to TSI time plateau (20-80% TTE) (r=0.83, p<0.05) and to TTE (r=0.95, p<0.001). The results of the present study show that the tissue oxygen saturation plateau might be affected by ventilatory work and that respiratory muscle endurance could be considered as a determinant of performance during heavy exercise.
authors.affiliation: EA-3300: APERE, Department of Sport Sciences, University of Picardie Jules Verne, Amiens, France. Electronic address: oueslati.ferid@hotmail.com.
authors.forename: Ferid
authors.initials: F
authors.lastname: Oueslati
authors.affiliation: Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Boone
authors.affiliation: EA-3300: APERE, Department of Sport Sciences, University of Picardie Jules Verne, Amiens, France.
authors.forename: Said
authors.initials: S
authors.lastname: Ahmaidi
mesh_terms: D005080:Exercise Test; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D012119:Respiration; D012132:Respiratory Muscles / Q000502:physiology*; D012420:Running / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared; D013147:Spirometry; D013997:Time Factors; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Exercise performance; Near infrared spectroscopy; Oxygen saturation index