title: Interval training program optimization in highly trained endurance cyclists.
abstract: OBJECTIVE
  The purpose of this study was to examine the influence of three different high-intensity interval training (HIT) regimens on endurance performance in highly trained endurance athletes.
  
  
  METHODS
  Before, and after 2 and 4 wk of training, 38 cyclists and triathletes (mean +/- SD; age = 25 +/- 6 yr; mass = 75 +/- 7 kg; VO(2peak) = 64.5 +/- 5.2 mL x kg(-1) min(-1)) performed: 1) a progressive cycle test to measure peak oxygen consumption (VO(2peak)) and peak aerobic power output (PPO), 2) a time to exhaustion test (T(max)) at their VO(2peak) power output (P(max)), as well as 3) a 40-km time-trial (TT(40)). Subjects were matched and assigned to one of four training groups (G(2), N = 8, 8 x 60% T(max) at P(max), 1:2 work:recovery ratio; G(2), N = 9, 8 x 60% T(max) at P(max), recovery at 65% HR(max); G(3), N = 10, 12 x 30 s at 175% PPO, 4.5-min recovery; G(CON), N = 11). In addition to G(1), G(2), and G(3) performing HIT twice per week, all athletes maintained their regular low-intensity training throughout the experimental period.
  
  
  RESULTS
  All HIT groups improved TT(40) performance (+4.4 to +5.8%) and PPO (+3.0 to +6.2%) significantly more than G(CON) (-0.9 to +1.1%; P < 0.05). Furthermore, G(1) (+5.4%) and G(2) (+8.1%) improved their VO(2peak) significantly more than G(CON) (+1.0%; P < 0.05).
  
  
  CONCLUSIONS
  The present study has shown that when HIT incorporates P(max) as the interval intensity and 60% of T(max) as the interval duration, already highly trained cyclists can significantly improve their 40-km time trial performance. Moreover, the present data confirm prior research, in that repeated supramaximal HIT can significantly improve 40-km time trial performance.
authors.affiliation: Human Performance Laboratory, School of Human Movement Studies, The University of Queensland, Brisbane, Australia. plaursen@hms.uq.edu.au
authors.forename: Paul B
authors.initials: PB
authors.lastname: Laursen
authors.forename: Cecilia M
authors.initials: CM
authors.lastname: Shing
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Peake
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Coombes
authors.forename: David G
authors.initials: DG
authors.lastname: Jenkins
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D000704:Analysis of Variance; D001642:Bicycling / Q000502:physiology*; D005080:Exercise Test; D006334:Heart Function Tests; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010806:Physical Education and Training / Q000379:methods*; D010807:Physical Endurance / Q000502:physiology*; D011336:Probability; D012016:Reference Values; D012129:Respiratory Function Tests; D012494:Sampling Studies; D012680:Sensitivity and Specificity