title: Ventilatory, lactate-derived and catecholamine thresholds during incremental treadmill running: relationship and reproducibility.
abstract: Anaerobic threshold as a basic criterion of training recommendation can be estimated by various parameters. The purpose of this study was to investigate the relationship and the reproducibility of ventilatory, lactate-derived and catecholamine thresholds of an incremental treadmill exercise. Therefore, 11 male subjects underwent two incremental treadmill tests within 7 days. The lactate threshold (LT) was determined at the lowest value of the lactate-equivalent (ratio lactate/performance). The individual anaerobic threshold (IAT) was calculated at LT+1.5 mmol/L lactate. The ventilatory thresholds, using mass-spectrometry, were defined by the V-slope method (AT) and at the deflection point of end-tidal CO2 (ET-CO2) concentration (RCP). The thresholds of epinephrine (TE) and norepinephrine (TNE) were calculated in the manner of LT. The running velocities were highly reproducible at LT (test-retest correlation coefficient r=0.90), IAT (r=0.97), AT (r=0.88) and RCP (r=0.95). By contrast TE (r=0.49) and TNE (r=0.46) showed a poor reproducibility. TE and TNE occurred 5-11% below LT and AT with a low correlation to LT and AT. LT was found 4% below AT, both were correlated with r=0.70 (p<0.01, test 1) and r=0.95 (p<0.01, test 2). IAT occurred 7-8% above RCP, in both tests a close correlation was found between IAT and RCP of r=0.97 (p<0.01). In summary, the ventilatory and lactate-derived thresholds show a high and similar reproducibility, but the catecholamine threshold does not. In the present exercise protocol, there are systematic differences between the lactate-derived and ventilatory thresholds, in spite of a close relationship, and these must be taken into account in recommendations derived for training.
authors: Medical Hospital and Policlinic, Department of Sport Medicine, University of Tübingen, Germany. hans-hermann.dickhuth@uni_tuebingen.de
authors: H H
authors: HH
authors: Dickhuth
authors: L
authors: L
authors: Yin
authors: A
authors: A
authors: Niess
authors: K
authors: K
authors: Röcker
authors: F
authors: F
authors: Mayer
authors: H C
authors: HC
authors: Heitkamp
authors: T
authors: T
authors: Horstmann
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold; D000886:Anthropometry; D001784:Blood Gas Analysis; D004837:Epinephrine / Q000097:blood*; D005080:Exercise Test; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009638:Norepinephrine / Q000097:blood*; D011659:Pulmonary Gas Exchange; D015203:Reproducibility of Results; D012119:Respiration
chemical_list: D019344:Lactic Acid; D009638:Norepinephrine; D004837:Epinephrine