title: Oral creatine supplementation's decrease of blood lactate during exhaustive, incremental cycling.
abstract: OBJECTIVE
  To determine the effects of creatine supplementation on blood lactate during incremental cycling exercise.
  
  
  METHODS
  Thirteen male subjects (M ± SD 23 ± 2 yr, 178.0 ± 8.1 cm, 86.3 ± 16.0 kg, 24% ± 9% body fat) performed a maximal, incremental cycling test to exhaustion before (Pre) and after (Post) 6 d of creatine supplementation (4 doses/d of 5 g creatine + 15 g glucose). Blood lactate was measured at the end of each exercise stage during the protocol, and the lactate threshold was determined as the stage before achieving 4 mmol/L. Lactate concentrations during the incremental test were analyzed using a 2 (condition) × 6 (exercise stage) repeated-measures ANOVA. Differences in power at lactate threshold, power at exhaustion, and total exercise time were determined by paired t tests and are presented as M ± SD.
  
  
  RESULTS
  Lactate concentrations were reduced during exercise after supplementation, demonstrating a significant condition effect (p = .041). There was a tendency for increased power at the lactate threshold (Pre 128 ± 45 W, Post 143 ± 26 W; p = .11). Total time to fatigue approached significant increases (Pre 22.6 ± 3.2 min, Post 23.3 ± 3.3 min; p = .056), as did maximal power output (Pre 212.5 ± 32.5 W, Post 220 ± 34.6 W; p = .082).
  
  
  CONCLUSIONS
  Our findings demonstrate that creatine supplementation decreases lactate during incremental cycling exercise and tends to raise lactate threshold. Therefore, creatine supplementation could potentially benefit endurance athletes.
authors.affiliation: Dept. of Kinesiology, Texas Christian University, Fort Worth, TX, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Oliver
authors.forename: Dustin P
authors.initials: DP
authors.lastname: Joubert
authors.forename: Steven E
authors.initials: SE
authors.lastname: Martin
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Crouse
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001642:Bicycling / Q000502:physiology*; D003401:Creatine / Q000008:administration & dosage*; D019587:Dietary Supplements; D005080:Exercise Test; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000187:drug effects; D055815:Young Adult
chemical_list: D019344:Lactic Acid; D003401:Creatine