title: Changes in blood lactate concentrations during different treadmill exercise test protocols.
abstract: OBJECTIVE
  The purpose of this study was to compare the blood-lactate and heart rate response of three treadmill tests and to define a conversion algorithm.
  
  
  METHODS
  Subjects included 19 long-distance runners. The first two tests had increments of 2 km/h every 3 (test3m) or 5 minutes (test5m). The third test (testFm) consisted of four consecutive 2000m-runs. The calculated individual-anaerobic-threshold (IAT) from test3m was defined as speed at the third step of testFm, speed-increments between the four steps were 0.25 m/s.
  
  
  RESULTS
  Lactate threshold (LT) did not show significant differences. Speed at IAT in test3m (15.09|*plusmn*|2.29 km/h) was significantly higher than in test5m (14.74|*plusmn*|2.22 km/h), heart rates were nearly identical. Speed and heart rate at 2 mmol/L showed no significant differences. At lactate concentrations of 3 and 4 mmol/L, running-speeds in test3m were significantly higher than in test5m and testFm. Heart rate were the same in test3m and test5m but significantly higher in testFm.
  
  
  CONCLUSIONS
  Taking test3m as basis for determining endurance-performance, an adjustment of test5m can be made by adding 1.8 mmol/l instead of 1.5 mmol/l to the LT to derive the IAT. TestFm shows similar results as test5m, however, standardization is difficult due to variable increment durations.
authors.affiliation: Department of Preventive and Rehabilitative Sports Medicine, University Hospital Freiburg, Freiburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Prettin
authors.forename: K
authors.initials: K
authors.lastname: Roecker
authors.forename: S
authors.initials: S
authors.lastname: Ruehl
authors.forename: P
authors.initials: P
authors.lastname: Deibert
authors.forename: Y O
authors.initials: YO
authors.lastname: Schumacher
authors.forename: A
authors.initials: A
authors.lastname: Hirschmüller
authors.forename: H-H
authors.initials: HH
authors.lastname: Dickhuth
mesh_terms: D000328:Adult; D000465:Algorithms; D005080:Exercise Test / Q000379:methods*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D010807:Physical Endurance / Q000502:physiology; D012420:Running / Q000502:physiology; D055815:Young Adult
chemical_list: D019344:Lactic Acid