title: The effect of exercise modality on respiratory muscle performance in triathletes.
abstract: OBJECTIVE
  The aim of this study was to examine the effects of the cycle-run and run-cycle successions of the triathlon and duathlon, respectively, on respiratory muscle strength and endurance.
  
  
  METHODS
  Respiratory muscle strength was assessed by measuring maximal inspiratory (P(Imax)) and expiratory (P(Emax)) pressures. Respiratory muscle endurance was assessed by measuring the time limit (T(lim)). Twelve triathletes participated in a three-trial protocol. The first trial consisted of an incremental cycle test to assess the maximal oxygen uptake (.VO(2max)) of triathletes. Trial 2 consisted of 20 min of cycling followed by 20 min of running (C-R), and trial 3 consisted of 20 min of running followed by 20 min of cycling (R-C). Trials 2 and 3 were performed at the same metabolic intensity (%.VO(2max)). P(Imax) and P(Emax) were measured before and 10 min after C-R and R-C, and 1 min after the post-C-R and post-R-C T(lim) measurements (P(Imax) 1'). T(lim) was measured 1 d before and 30 min after C-R and R-C.
  
  
  RESULTS
  The results showed a significant decrease in P(Imax) after C-R (126.7 +/- 4.3 cmH(2)O, P < 0.05) and R-C (123.7 +/- 4.9 cmH(2)O, P < 0.05) compared with the baseline values (130 +/- 3.8 and 129.6 +/- 4.3 cmH(2)O, respectively). P(Imax) 1' showed a significantly greater decrease after R-C versus C-R (111.2 +/- 5.5 cmH(2)O vs 121.2 +/- 3.9 cmH(2O), respectively, P < 0.001). Tlim after C-R (3.3 +/- 0.3 min) and R-C (2.1 +/- 0.3 min) decreased significantly compared with baseline values (4.19 +/- 0.3 min and 4.02 +/- 0.3 min, respectively). However, the Tlim decrease after R-C was significantly greater than after C-R (P < 0.001).
  
  
  CONCLUSIONS
  We concluded that respiratory muscle strength and endurance were less decreased after the cycle-run succession and that cycling induced a greater decrease in respiratory muscle endurance than running.
authors.affiliation: Laboratoire Sport Performance Santé, Faculté des Sciences du Sport, 700 Avenue du Pic Saint Loup, F-34090 Montpellier, France.
authors.forename: A
authors.initials: A
authors.lastname: Boussana
authors.forename: S
authors.initials: S
authors.lastname: Matecki
authors.forename: O
authors.initials: O
authors.lastname: Galy
authors.forename: O
authors.initials: O
authors.lastname: Hue
authors.forename: M
authors.initials: M
authors.lastname: Ramonatxo
authors.forename: D
authors.initials: D
authors.lastname: Le Gallais
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D011187:Posture / Q000502:physiology; D012132:Respiratory Muscles / Q000502:physiology*; D012420:Running / Q000502:physiology*; D013147:Spirometry