title: Intermittent-sprint performance and muscle glycogen after 30 h of sleep deprivation.
abstract: OBJECTIVE
  The aim of this study was to determine the effects of 30 h of sleep deprivation on consecutive-day intermittent-sprint performance and muscle glycogen content.
  
  
  METHODS
  Ten male, team-sport athletes performed a single-day "baseline" session and two consecutive-day experimental trials separated either by a normal night's sleep (CONT1 and CONT2) or no sleep (SDEP1 and SDEP2). Each session included a 30-min graded exercise run and 50-min intermittent-sprint exercise protocol, including a 15-m maximal sprint every minute and self-paced exercise bouts of varying intensities. Muscle biopsies were extracted before and after exercise during the baseline session and before exercise on day 2 during experimental trials. Voluntary force and activation of the right quadriceps, nude mass, HR, core temperature, capillary blood lactate and glucose, RPE, and a modified POMS were recorded before, after, and during the exercise protocols.
  
  
  RESULTS
  Mean sprint times were slower on SDEP2 (2.78±0.17 s) compared with SDEP1 (2.70±0.16 s) and CONT2 (2.74±0.15 s, P<0.05). Distance covered during self-paced exercise was reduced during SDEP2 during the initial 10 min compared with SDEP1 and during the final 10 min compared with CONT2 (P<0.05). Muscle glycogen concentration was lower before exercise on SDEP2 (209±60 mmol·kg dry weight) compared with CONT2 (274±54 mmol·kg dry weight, P=0.05). Voluntary force and activation were reduced on day 2 of both conditions; however, both were lower in SDEP2 compared with CONT2 (P<0.05). Sleep loss did not affect RPE but negatively affected POMS ratings (P<0.05).
  
  
  CONCLUSIONS
  Sleep loss and associated reductions in muscle glycogen and perceptual stress reduced sprint performance and slowed pacing strategies during intermittent-sprint exercise for male team-sport athletes.
authors.affiliation: School of Human Movement Studies, Charles Sturt University, Bathurst, NSW, Australia. mskein@csu.edu.au
authors.forename: Melissa
authors.initials: M
authors.lastname: Skein
authors.forename: Rob
authors.initials: R
authors.lastname: Duffield
authors.forename: Johann
authors.initials: J
authors.lastname: Edge
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Short
authors.forename: Toby
authors.initials: T
authors.lastname: Mündel
mesh_terms: D000293:Adolescent; D056352:Athletes; D054874:Athletic Performance; D001786:Blood Glucose / Q000502:physiology; D001831:Body Temperature / Q000502:physiology; D006003:Glycogen / Q000032:analysis / Q000378:metabolism*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism*; D012420:Running / Q000502:physiology*; D012892:Sleep Deprivation / Q000378:metabolism*; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid; D006003:Glycogen