title: The 1-min sit-to-stand test in cystic fibrosis - Insights into cardiorespiratory responses.
abstract: BACKGROUND
  We aimed to characterize the cardiopulmonary response during a 1-min sit-to-stand (STS) test and compare peak exercise cardiorespiratory variables to a maximal cardiopulmonary exercise test (CPET) in cystic fibrosis (CF). We further aimed to assess the validity of the STS power index (PowerSTS) as a measure of exercise capacity.
  
  
  METHODS
  Fifteen adult CF patients performed spirometry, CPET and the 1-min STS test with respiratory gas analysis.
  
  
  RESULTS
  Peak-exercise cardiorespiratory variables during the 1-min STS test correlated strongly (r=0.69-0.98) with those measured during the CPET. Oxygen uptake, carbon dioxide production, heart rate, ventilation, and tidal volume at peak exercise were 24%, 26%, 9%, 10% and 21% lower in the 1-min STS test, while respiratory frequencies were 14% higher. PowerSTSshowed strong to very strong correlations with CPET-derived absolute peak oxygen uptake and maximal workload.
  
  
  CONCLUSIONS
  The 1-min STS test elicits a substantial but lower cardiorespiratory response compared to a maximal cycle ergometry CPET. While PowerSTSand STS repetitions are both valid outcome measures of functional capacity, STS repetitions are clinically more practical.
authors.affiliation: Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zurich, Switzerland. Electronic address: thomas.radtke@uzh.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Radtke
authors.affiliation: Paediatric Department, Julius-Maximilians University Würzburg, Wuerzburg, Germany.
authors.forename: Helge
authors.initials: H
authors.lastname: Hebestreit
authors.affiliation: Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zurich, Switzerland.
authors.forename: Milo A
authors.initials: MA
authors.lastname: Puhan
authors.affiliation: Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zurich, Switzerland.
authors.forename: Susi
authors.initials: S
authors.lastname: Kriemler
mesh_terms: D000328:Adult; D001944:Breath Tests / Q000379:methods*; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000503:physiopathology; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D012123:Pulmonary Ventilation / Q000502:physiology; D015203:Reproducibility of Results; D013147:Spirometry / Q000379:methods*; D013223:Statistics as Topic
keywords: Exercise testing; Functional capacity; Lung disease; Validity