title: Metabolism and performance in repeated cycle sprints: active versus passive recovery.
abstract: OBJECTIVE
  To compare active versus passive recovery on performance and metabolism during a test of repeated-sprint ability.
  
  
  METHODS
  Nine males performed four repeated-sprint cycle tests (six 4-s sprints, every 25 s) in a randomized, counterbalanced order: two tests with active recovery (approximately 32% VO2max) and two with passive recovery. Muscle biopsies were taken during the four tests from the vastus lateralis pretest, immediately posttest, and following 21 s of recovery to determine phosphocreatine ([PCr]), creatine, and muscle lactate concentration ([MLa]).
  
  
  RESULTS
  Active recovery resulted in a greater power decrement than passive recovery (7.4 +/- 2.2 vs 5.6 +/- 1.8%, P = 0.01) and lower final peak power (14.9 +/- 1.5 vs 15.3 +/- 1.5 W.kg(-1), P = 0.02). However, there was no significant difference in work decrement or total work. The percent of resting [PCr] was lower and approached significance posttest (32.6 +/- 10.6 vs 45.3 +/- 18.6%; P = 0.06; effect size (ES) = 0.8) and following 21 s of recovery (54.6 +/- 9.6 vs 71.7 +/- 14.1%; P = 0.06; ES = 1.2) during active recovery. The [MLa] was significantly higher posttest during active recovery (71.7 +/- 12.3 vs 55.2 +/- 15.7 mmol.kg(-1)dm; P = 0.048; ES = 1.2); however, no significant differences were evident following 21 s of recovery (55.0 +/- 11.3 vs 48.4 +/- 16.7 mmol.kg(-1)dm, P = 0.07; ES = 0.5).
  
  
  CONCLUSIONS
  Despite no differences in the majority of performance measures, active recovery resulted in a significantly lower final peak power, a greater peak power decrement, a higher [MLa], and a strong trend towards lower [PCr], suggesting a potential suboptimal effect of active recovery during repeated-sprint exercise.
authors.affiliation: Team Sport Research Group, School of Human Movement and Exercise Science, The University of Western Australia, Crawley, Australia. mspencer@wais.org.au
authors.forename: Matt
authors.initials: M
authors.lastname: Spencer
authors.forename: David
authors.initials: D
authors.lastname: Bishop
authors.forename: Brian
authors.initials: B
authors.lastname: Dawson
authors.forename: Carmel
authors.initials: C
authors.lastname: Goodman
authors.forename: Rob
authors.initials: R
authors.lastname: Duffield
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001642:Bicycling / Q000502:physiology*; D001706:Biopsy; D003401:Creatine / Q000378:metabolism; D005080:Exercise Test; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D010725:Phosphocreatine / Q000378:metabolism; D005082:Physical Exertion / Q000502:physiology*; D015203:Reproducibility of Results
chemical_list: D007773:Lactates; D010725:Phosphocreatine; D003401:Creatine