Relationships between maximal muscle oxidative capacity and blood lactate removal after supramaximal exercise and fatigue indexes in humans

• Published in: Journal of applied physiology (1985) 2004-12, Vol.97 (6), p.2132-2138
• Main Authors: Thomas, C, Sirvent, P, Perrey, S, Raynaud, E, Mercier, J
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Exercise; Fatigue; Fundamental and applied biological sciences. Psychology; Glutamic Acid - metabolism; Human health and pathology; Humans; Lactic Acid - blood; Life Sciences; Malates - metabolism; Male; Mitochondria - metabolism; Muscle Contraction - physiology; Muscle Fatigue - physiology; Muscle Fibers, Skeletal - metabolism; Muscle, Skeletal - cytology; Muscle, Skeletal - metabolism; Muscular system; Oxidation-Reduction; Oxygen; Physical Exertion - physiology; Tissues and Organs
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00387.2004

1 Laboratoire de Physiologie des Interactions (EA 701), Département de Physiologie, Institut de Biologie, 34060 Montpellier; and 2 Efficience et Déficience Motrice (EA 2991), 34090 Montpellier, France Submitted 8 April 2004 ; accepted in final form 16 June 2004 The present study investigated whether blood lactate removal after supramaximal exercise and fatigue indexes measured during continuous and intermittent supramaximal exercises are related to the maximal muscle oxidative capacity in humans with different training status. Lactate recovery curves were obtained after a 1-min all-out exercise. A biexponential time function was then used to determine the velocity constant of the slow phase ( 2 ), which denoted the blood lactate removal ability. Fatigue indexes were calculated during all-out (FI AO ) and repeated 10-s cycling sprints (FI Sprint ). Biopsies were taken from the vastus lateralis muscle, and maximal ADP-stimulated mitochondrial respiration ( V max ) was evaluated in an oxygraph cell on saponin-permeabilized muscle fibers with pyruvate + malate and glutamate + malate as substrates. Significant relationships were found between 2 and pyruvate + malate V max ( r = 0.60, P < 0.05), 2 and glutamate + malate V max ( r = 0.66, P < 0.01), and 2 and citrate synthase activity ( r = 0.76, P < 0.01). In addition, 2 , glutamate + malate V max , and pyruvate + malate V max were related to FI AO ( 2 – FI AO : r = 0.85; P < 0.01; glutamate + malate V max – FI AO : r = 0.70, P < 0.01; and pyruvate + malate V max – FI AO : r = 0.63, P < 0.01) and FI Sprint ( 2 – FI Sprint : r = 0.74, P < 0.01; glutamate + malate V max – FI Sprint : r = 0.64, P < 0.01; and pyruvate + malate V max – FI Sprint : r = 0.46, P < 0.01). In conclusion, these results suggested that the maximal muscle oxidative capacity was related to blood lactate removal ability after a 1-min all-out test. Moreover, maximal muscle oxidative capacity and blood lactate removal ability were associated with the delay in the fatigue observed during continuous and intermittent supramaximal exercises in well-trained subjects. lactate kinetics; biexponential mathematical model; all-out exercise; saponin-permeabilized muscle fibers Address for reprint requests and other correspondence: C. Thomas, Laboratoire de Physiologie des Interactions (EA 701), Département de Physiologie, Institut de Biologie, Bvd Henri IV, 34060 Montpellier Cedex 2, France (E-mail: thomasclaire{at}wanadoo.fr )