title: Reliability of urine lactate as a novel biomarker of lactate production capacity in maximal swimming.
abstract: BACKGROUND
  Postexercise urine lactate may be a novel biomarker of lactate production capacity during exercise.
  
  
  OBJECTIVE
  To evaluate the reliability and utility of the urine lactate concentration after maximal swimming trials between different training protocols (6 × 50 m and 3 × 100 m) and training states (active and nonactive swimmers).
  
  
  METHODS
  Lactate and creatinine were determined by spectrophotometry in blood and urine.
  
  
  RESULTS
  Blood and urine lactate concentrations were correlated in-between training protocols and in participants of different training states. The reliability of the urine lactate concentration was moderate for one of the training protocols and good or moderate for the two training states. Additionally, it was lower than that of the blood lactate concentration, and did not improve after normalizing to the urine creatinine concentration.
  
  
  CONCLUSIONS
  Although promising as a biomarker of lactate production capacity, urine lactate requires further research to improve its reliability.
authors: a School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki , Greece.
authors: Stefanos
authors: S
authors: Nikolaidis
authors: a School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki , Greece.
authors: Christina
authors: C
authors: Karpouzi
authors: a School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki , Greece.
authors: George
authors: G
authors: Tsalis
authors: a School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki , Greece.
authors: Athanasios
authors: A
authors: Kabasakalis
authors: a School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki , Greece.
authors: Konstantinos G
authors: KG
authors: Papaioannou
authors: a School of Physical Education and Sport Science at Thessaloniki, Aristotle University of Thessaloniki , Greece.
authors: Vassilis
authors: V
authors: Mougios
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood / Q000652:urine*; D006801:Humans; D019344:Lactic Acid / Q000096:biosynthesis / Q000097:blood / Q000652:urine*; D008297:Male; D013550:Swimming
chemical_list: D015415:Biomarkers; D019344:Lactic Acid
keywords: Swimming; anaerobic capacity; intraclass correlation coefficient; reliability; test–retest