title: Reliability of the maximal oxygen uptake following two consecutive trials by indirect calorimetry.
abstract: BACKGROUND
  The maximal oxygen uptake (VO2máx) assessment by indirect calorimetry is the most reliable method to determine VO2máx, but when repeated tests are conducted, the results have been controversial.
  
  
  OBJECTIVE
  To determine the reliability of the maximal oxygen uptake (VO2máx) in healthy adults following two consecutive trials with 10 min rest between trials using the Bruce protocol.
  
  
  METHODS
  Participants were 6 males apparently healthy physically active (Mean age=23,4±1,3 years), who performed twice the Bruce protocol and after reaching their VO2máx in the first trial they stepped down the treadmill and rested seated on a chair during 10 min.
  
  
  RESULTS
  The data analysis showed high reproducibility values between tests, indicated by the correlation coefficient Pearson product moment and R squared with confidence intervals at 95% (CI95%), the correlation of the maximum oxygen consumption was VO2máx =0.907 with a R2=0.823, the maximum heart rate was HRmáx=0.786, with R2=0.618 and the rate of ventilation and carbon dioxide elimination was VE/VCO2=0.868, with an R2=754. No adverse effects were reported during the 10 min rest between trials.
  
  
  CONCLUSIONS
  Resting 10 min between consecutive maximal exercise tests using Bruce protocol treadmill tests does not affect VO2máx in healthy young adults. It is feasible and reliable to perform maximal treadmill tests in a single session without adverse effects for the participant.
authors: Facultad de Deportes, Universidad Autónoma de Baja California. México.. javierhall@uabc.edu.mx.
authors: Javier Arturo
authors: JA
authors: Hall-López
authors: Facultad de Deportes, Universidad Autónoma de Baja California. México.. pochoa@uabc.edu.mx.
authors: Paulina Yesica
authors: PY
authors: Ochoa-Martínez
authors: Facultad de Deportes, Universidad Autónoma de Baja California. México.. pochoa@uabc.edu.mx.
authors: José
authors: J
authors: Moncada-Jiménez
authors: Centro de Investigación en Ciencias del Movimiento Humano, Universidad de Costa Rica. Costa Rica.. pochoa@uabc.edu.mx.
authors: Mara Alessandra
authors: MA
authors: Ocampo Méndez
authors: Facultad de Deportes, Universidad Autónoma de Baja California. México.. pochoa@uabc.edu.mx.
authors: Issael
authors: I
authors: Martínez García
authors: Facultad de Deportes, Universidad Autónoma de Baja California. México.. pochoa@uabc.edu.mx.
authors: Marco Antonio
authors: MA
authors: Martínez García
mesh_terms: D015308:Anaerobic Threshold / Q000502:physiology*; D002153:Calorimetry, Indirect / Q000379:methods*; D002245:Carbon Dioxide / Q000378:metabolism; D005080:Exercise Test; D006339:Heart Rate; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide