title: Gas exchange kinetics following concentric-eccentric isokinetic arm and leg exercise.
abstract: To evaluate the effects of exercise velocity (60, 150, 240deg∙s-1) and muscle mass (arm vs leg) on changes in gas exchange and arterio-venous oxygen content difference (avDO2) following high-intensity concentric-eccentric isokinetic exercise.
  
  
  
  Fourteen subjects (26.9±3.1years) performed a 3×20-repetition isokinetic exercise protocol. Recovery beat-to-beat cardiac output (CO) and breath-by-breath gas exchange were recorded to determine post-exercise half-time (t1/2) for oxygen uptake (V˙O2pulm), carbon dioxide output (V˙CO2pulm), and ventilation (V˙E).
  
  
  
  Significant differences of the t1/2values were identified between 60 and 150deg∙s-1. Significant differences in the t1/2values were observed between V˙O2pulm and V˙CO2pulm and between V˙CO2pulm and V˙E. The time to attain the first avDO2-peak showed significant differences between arm and leg exercise.
  
  
  
  The present study illustrates, that V˙O2pulm kinetics are distorted due to non-linear CO dynamics. Therefore, it has to be taken into account, that V˙O2pulm may not be a valuable surrogate for muscular oxygen uptake kinetics in the recovery phases.
authors.affiliation: Institute of Physiology and Anatomy, Am Sportpark Müngersdorf 6, German Sport University Cologne, Cologne, 50933, Germany. Electronic address: Drescher@dshs-koeln.de.
authors.forename: U
authors.initials: U
authors.lastname: Drescher
authors.affiliation: Department of Exercise Science, 400 E. 2nd St, Bloomsburg University, Bloomsburg, PA, 17815, USA.
authors.forename: S
authors.initials: S
authors.lastname: Mookerjee
authors.affiliation: Institute of Physiology and Anatomy, Am Sportpark Müngersdorf 6, German Sport University Cologne, Cologne, 50933, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Steegmanns
authors.affiliation: Institute of Movement and Neuroscience, Am Sportpark Müngersdorf 6, German Sport University Cologne, Cologne, 50933, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Knicker
authors.affiliation: Institute of Physiology and Anatomy, Am Sportpark Müngersdorf 6, German Sport University Cologne, Cologne, 50933, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Hoffmann
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001132:Arm / Q000502:physiology*; D002302:Cardiac Output; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D007866:Leg / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D012119:Respiration; D055815:Young Adult
keywords: Oxygen uptake kinetics; Recovery phase; Resistance exercise; Skeletal muscle