Effect of prior exercise on pulmonary O2 uptake and estimated muscle capillary blood flow kinetics during moderate-intensity field running in men

• Published in: Journal of applied physiology (1985) 2009-08, Vol.107 (2), p.460-470
• Main Authors: Buchheit, Martin, Laursen, Paul B, Ahmaidi, Said
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological; Adult; Anaerobic Threshold; Biological and medical sciences; Breath Tests; Capillaries - physiology; Exercise; Fundamental and applied biological sciences. Psychology; Heart Rate; Hemoglobins - metabolism; Humans; Kinetics; Lactic Acid - blood; Male; Microcirculation; Models, Biological; Muscle Contraction; Myoglobin - metabolism; Oxygen - blood; Oxygen Consumption; Pulmonary Ventilation; Quadriceps Muscle - blood supply; Quadriceps Muscle - metabolism; Regional Blood Flow; Running; Spectroscopy, Near-Infrared; Young Adult
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.91625.2008

1 Laboratory of Exercise Physiology and Rehabilitation, EA 3300, Faculty of Sport Sciences, University of Picardie, Jules Verne, Amiens, France; and 2 School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia Submitted 19 December 2008 ; accepted in final form 2 June 2009 The effect of prior exercise on pulmonary O 2 uptake ( O 2 p ) and estimated muscle capillary blood flow ( m ) kinetics during moderate-intensity, field-based running was examined in 14 young adult men, presenting with either moderately fast (16 s < O 2 p < 30 s; MFK) or very fast O 2 p kinetics ( O 2 p < 16 s; VFK) (i.e., primary time constant, O 2 p ). On four occasions, participants completed a square-wave protocol involving two bouts of running at 90–95% of estimated lactate threshold (Mod 1 and Mod 2 ), separated by 2 min of repeated supramaximal sprinting. O 2 p was measured breath by breath, heart rate (HR) beat to beat, and vastus lateralis oxygenation {deoxy-hemoglobin/myoglobin concentration (deoxy-[Hb+Mb])} using near-infrared spectroscopy. Mean response time of m ( m MRT) was estimated by rearranging the Fick equation, using O 2 p and deoxy-[Hb+Mb] as proxies of muscle O 2 uptake ( O 2 ) and arteriovenous difference, respectively. HR, blood lactate concentration, total hemoglobin, and m were elevated before Mod 2 compared with Mod 1 (all P < 0.05). O 2 p was shorter in VFK compared with MFK during Mod 1 (13.1 ± 1.8 vs. 21.0 ± 2.5 s, P < 0.01), but not in Mod 2 (12.9 ± 1.5 vs. 13.7 ± 3.8 s, P = 1.0). m MRT was shorter in VFK compared with MFK in Mod 1 (8.8 ± 1.9 vs. 17.0 ± 3.4 s, P < 0.01), but not in Mod 2 (10.1 ± 1.8 vs. 10.5 ± 3.5 s, P = 1.0). During Mod 2 , HR kinetics were slowed, whereas mean deoxy-[Hb+Mb] response time was unchanged. The difference in O 2 p between Mod 1 and Mod 2 was related to m MRT measured at Mod 1 ( r = 0.71, P < 0.01). Present results suggest that local O 2 delivery (i.e., m ) may be a factor contributing to the O 2 kinetic during the onset of moderate-intensity, field-based running exercise, at least in subjects exhibiting moderately fast O 2 kinetics. oxygen uptake dynamics; near-infrared spectroscopy; muscle deoxygenation; repeated sprint exercise; warm-up Address for reprint requests and other correspondence: M. Buchheit, Research Laboratory, EA 3300 Exercise Physiology and Rehabilitation , Faculty of Sport Sciences, Univ. of Picardie, Jules Verne, F-80025, Amiens, France (e-mail: martin