title: Prediction of maximal lactate steady state in runners with an incremental test on the field.
abstract: During a maximal incremental ergocycle test, the power output associated with Respiratory Exchange Ratio equal to 1.00 (RER = 1.00) predicts maximal lactate steady state (MLSS). We hypothesised that these results are transferable for runners on the field. Fourteen runners performed a maximal progressive test, to assess the speed associated with RER = 1.00, and several 30 minutes constant velocity tests to determine the speed at MLSS. We observed that the speeds at RER = 1.00, at the second ventilatory threshold (VT2) and at MLSS did not differ (15.7 ± 1.1 km · h⁻¹, 16.2 ± 1.4 km · h⁻¹, 15.5 ± 1.1 km · h⁻¹ respectively). The speed associated with RER = 1.00 was better correlated with that at MLSS (r = 0.79; p = 0.0008) than that at VT2 (r = 0.73; p = 0.002). Neither the concentration of blood lactate nor the heart rate differed between the speed at RER = 1.00 and that at MLSS from the 10th and the 30th minute of the constant velocity test. Bland and Altman analysis showed a fair agreement between the speed at MLSS and that at RER (0.2 ± 1.4 km · h⁻¹). This study demonstrated that the speed associated with RER = 1.00 determined during maximal progressive track running allows a fair estimation of the speed associated with MLSS, markedly decreasing the burden of numerous invasive tests required to assess it.
authors.affiliation: Joseph Fourier University, Hypoxia Physiopathology laboratory, Grenoble, F-38000, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Leti
authors.forename: Monique
authors.initials: M
authors.lastname: Mendelson
authors.forename: David
authors.initials: D
authors.lastname: Laplaud
authors.forename: Patrice
authors.initials: P
authors.lastname: Flore
mesh_terms: D001642:Bicycling / Q000502:physiology*; D005080:Exercise Test; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D005082:Physical Exertion / Q000502:physiology*; D012119:Respiration; D012420:Running / Q000502:physiology*; D055815:Young Adult
chemical_list: D019344:Lactic Acid