title: Lactate recovery kinetics in response to high-intensity exercises.
abstract: OBJECTIVE
  The aim of this study was to investigate lactate recovery kinetics after high-intensity exercises.
  
  
  METHODS
  Six competitive middle-distance runners performed 500-, 1000-, and 1500-m trials at 90 % of their current maximal speed over 1500 m. Each event was followed by a passive recovery to obtain blood lactate recovery curves (BLRC). BLRC were fitted by the bi-exponential time function: La(t) = La(0) + A 1(1-e (-γ1t) ) + A 2(1-e (-γ2t) ), where La(0) is the blood lactate concentration at exercise completion, and γ 1 and γ 2 enlighten the lactate exchange ability between the previously active muscles and the blood and the overall lactate removal ability, respectively. Applications of the model provided parameters related to lactate release, removal and accumulation rates at exercise completion, and net amount of lactate released during recovery.
  
  
  RESULTS
  The increase of running distance was accompanied by (1) a continuous decrease in γ 1 (p < 0.05), (2) a primary decrease (p < 0.05) and then a stabilization of γ 2, and (3) a constant increase in blood concentrations (p < 0.05) and whole body accumulation of lactate (p < 0.05). Estimated net lactate release, removal and accumulation rates at exercise completion, as well as the net amount of lactate released during recovery were not significantly altered by distance.
  
  
  CONCLUSIONS
  Alterations of lactate exchange and removal abilities have presumably been compensated by an increase in muscle-to-blood lactate gradient and blood lactate concentrations, respectively, so that estimated lactate release, removal and accumulation rates remained almost stable as distance increased.
authors.affiliation: Laboratoire Interuniversitaire de Biologie de la Motricité, Université Savoie Mont Blanc, Campus Universitaire Savoie Technolac, Le Bourget-du-Lac cedex, 73376, Chambéry, France.|Aix-Marseille Université, CNRS, CRMBM UMR 7339, 13385, Marseille, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Chatel
authors.affiliation: Laboratoire Interuniversitaire de Biologie de la Motricité, Université Savoie Mont Blanc, Campus Universitaire Savoie Technolac, Le Bourget-du-Lac cedex, 73376, Chambéry, France.|Laboratoire d'Ingénierie et Sciences des Matériaux, Université de Reims Champagne-Ardenne, Reims, France.
authors.forename: Carine
authors.initials: C
authors.lastname: Bret
authors.affiliation: Laboratoire Interuniversitaire de Biologie de la Motricité, Université de Lyon, Université Jean Monnet, Saint-Étienne, France.|Unité de Médecine du Sport, Département de Physiologie Clinique et de l'Exercice, Centre Hospitalier Universitaire de Saint-Etienne, Saint-Étienne, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Edouard
authors.affiliation: Laboratoire Interuniversitaire de Biologie de la Motricité, Université de Lyon, Université Jean Monnet, Saint-Étienne, France.
authors.forename: Roger
authors.initials: R
authors.lastname: Oullion
authors.affiliation: Laboratoire Interuniversitaire de Biologie de la Motricité, Université Savoie Mont Blanc, Campus Universitaire Savoie Technolac, Le Bourget-du-Lac cedex, 73376, Chambéry, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Freund
authors.affiliation: Laboratoire Interuniversitaire de Biologie de la Motricité, Université Savoie Mont Blanc, Campus Universitaire Savoie Technolac, Le Bourget-du-Lac cedex, 73376, Chambéry, France. laurent.messonnier@univ-smb.fr.|Aix-Marseille Université, CNRS, CRMBM UMR 7339, 13385, Marseille, France. laurent.messonnier@univ-smb.fr.
authors.forename: Laurent A
authors.identifier: http://orcid.org/0000-0001-8823-1986
authors.initials: LA
authors.lastname: Messonnier
mesh_terms: D003198:Computer Simulation; D015444:Exercise / Q000502:physiology; D006801:Humans; D007700:Kinetics; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D012420:Running / Q000502:physiology*; D055815:Young Adult
chemical_list: D019344:Lactic Acid
keywords: Bi-compartmental model; Lactate exchanges; Lactate removal; Middle-distance running