STUDY OBJECTIVES: In patients with moderate-to-severe COPD, an encouraged 6-min walking test (6MWT) is a high-intensity submaximal exercise protocol that shows an oxygen uptake (Vo(2)) plateau after the third minute of the test. This last feature prompted the hypothesis that self-paced walking speed is set to achieve "maximal" sustainable Vo(2), namely "critical power" or "critical speed." PATIENTS AND METHODS: Eight patients with moderate-to-severe COPD (mean age, 68 +/- 7 years [+/- SD]; FEV(1), 50 +/- 13% predicted; Pao(2), 69 +/- 8 mm Hg) underwent the following tests on different days in order: (1) encouraged 6MWT; (2) standard incremental shuttle test to identify peak walking speed; (3) four different high-intensity, constant walking speed tests to exhaustion to calculate critical walking speed; and (4) timed walking test at critical walking speed (CWS) to examine sustainability of the exercise. RESULTS: 6MWT and CWS showed similar results (mean of last 3 min): Vo(2) (1,605 +/- 304 mL/min vs 1,584 +/- 319 mL/min), minute ventilation (47 +/- 12 L/min vs 48 +/- 11 L/min), respiratory exchange ratio (0.89 +/- 0.1 vs 0.90 +/- 0.1), heart rate (130 +/- 18 beats/min vs 131 +/- 16 beats/min), Borg dyspnea score (5.4 +/- 1.3 vs 5.5 +/- 2.4), and walking speed (1.49 +/- 0.1 m/s vs 1.44 +/- 0.1 m/s, respectively). CONCLUSION: This study supports that 6MWT indicates maximum sustainable exercise that might be related with its predictive value in COPD patients.
STUDY OBJECTIVES: In patients with moderate-to-severe COPD, an encouraged 6-min walking test (6MWT) is a high-intensity submaximal exercise protocol that shows an oxygen uptake (Vo(2)) plateau after the third minute of the test. This last feature prompted the hypothesis that self-paced walking speed is set to achieve "maximal" sustainable Vo(2), namely "critical power" or "critical speed." PATIENTS AND METHODS: Eight patients with moderate-to-severe COPD (mean age, 68 +/- 7 years [+/- SD]; FEV(1), 50 +/- 13% predicted; Pao(2), 69 +/- 8 mm Hg) underwent the following tests on different days in order: (1) encouraged 6MWT; (2) standard incremental shuttle test to identify peak walking speed; (3) four different high-intensity, constant walking speed tests to exhaustion to calculate critical walking speed; and (4) timed walking test at critical walking speed (CWS) to examine sustainability of the exercise. RESULTS: 6MWT and CWS showed similar results (mean of last 3 min): Vo(2) (1,605 +/- 304 mL/min vs 1,584 +/- 319 mL/min), minute ventilation (47 +/- 12 L/min vs 48 +/- 11 L/min), respiratory exchange ratio (0.89 +/- 0.1 vs 0.90 +/- 0.1), heart rate (130 +/- 18 beats/min vs 131 +/- 16 beats/min), Borg dyspnea score (5.4 +/- 1.3 vs 5.5 +/- 2.4), and walking speed (1.49 +/- 0.1 m/s vs 1.44 +/- 0.1 m/s, respectively). CONCLUSION: This study supports that 6MWT indicates maximum sustainable exercise that might be related with its predictive value in COPDpatients.
Authors: José Luis Lopez-Campos; Pilar Cejudo; Eduardo Marquez; Francisco Ortega; Esther Quintana; Carmen Carmona; Emilia Barrot Journal: Int J Chron Obstruct Pulmon Dis Date: 2010-05-06
Authors: Lukas Kern; Sophie Condrau; Florent Baty; Jan Wiegand; Arno J R van Gestel; Andrea Azzola; Michael Tamm; Martin Brutsche Journal: BMC Pulm Med Date: 2014-10-29 Impact factor: 3.317
Authors: Vasileios Andrianopoulos; Scott S Wagers; Miriam T J Groenen; Lowie E Vanfleteren; Frits M E Franssen; Frank W J M Smeenk; Ioannis Vogiatzis; Emiel F M Wouters; Martijn A Spruit Journal: BMC Pulm Med Date: 2014-05-31 Impact factor: 3.317
Authors: J M Grosbois; C Riquier; B Chehere; J Coquart; H Béhal; F Bart; B Wallaert; C Chenivesse Journal: Int J Chron Obstruct Pulmon Dis Date: 2016-03-29