title: Decrease of O(2) deficit is a potential factor in increased time to exhaustion after specific endurance training.
abstract: The main purpose of this study was to investigate the effects of an 8-wk severe interval training program on the parameters of oxygen uptake kinetics, such as the oxygen deficit and the slow component, and their potential consequences on the time until exhaustion in a severe run performed at the same absolute velocity before and after training. Six endurance-trained runners performed, on a 400-m synthetic track, an incremental test and an all-out test, at 93% of the velocity at maximal oxygen consumption, to assess the time until exhaustion. These tests were carried out before and after 8 wk of a severe interval training program, which was composed of two sessions of interval training at 93% of the velocity at maximal oxygen consumption and three recovery sessions of continuous training at 60--70% of the velocity at maximal oxygen consumption per week. Neither the oxygen deficit nor the slow component were correlated with the time until exhaustion (r = -0.300, P = 0.24, n = 18 vs. r = -0.420, P = 0.09, n = 18, respectively). After training, the oxygen deficit significantly decreased (P = 0.02), and the slow component did not change (P = 0.44). Only three subjects greatly improved their time until exhaustion (by 10, 24, and 101%). The changes of oxygen deficit were significantly correlated with the changes of time until exhaustion (r = -0.911, P = 0.01, n = 6). It was concluded that the decrease of oxygen deficit was a potential factor for the increase of time until exhaustion in a severe run performed after a specific endurance-training program.
authors.affiliation: Laboratoire d'Etude de la Motricité Humaine, Faculté des Sciences du Sport, Université de Lille 2, 59790 Ronchin, France.
authors.forename: A P
authors.initials: AP
authors.lastname: Demarle
authors.forename: J J
authors.initials: JJ
authors.lastname: Slawinski
authors.forename: L P
authors.initials: LP
authors.lastname: Laffite
authors.forename: V G
authors.initials: VG
authors.lastname: Bocquet
authors.forename: J P
authors.initials: JP
authors.lastname: Koralsztein
authors.forename: V L
authors.initials: VL
authors.lastname: Billat
mesh_terms: D000328:Adult; D000332:Aerobiosis; D000704:Analysis of Variance; D006801:Humans; D007773:Lactates / Q000097:blood; D008433:Mathematics; D008954:Models, Biological; D018763:Muscle Fatigue; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D015203:Reproducibility of Results; D012129:Respiratory Function Tests; D012420:Running / Q000502:physiology*; D013997:Time Factors
chemical_list: D007773:Lactates