Good repeatability ( for the 6MWT and ESWT ) and reproducibility ( for the 6MWT , 12-minute walk test , ISWT , ESWT , and incremental cycle ergometer test ) were reported by most studies assessing these tests , providing patients were familiarized with them beforeh and .
The 6MWT , ISWT , and particularly the ESWT were reported to be sensitive to therapeutic intervention .
Exercise tests are often used to evaluate the functional status of patients with COPD .
However , to the best of our knowledge , a comprehensive systematic comparison of these tests has not been performed .
We systematic ally review ed studies reporting the repeatability and /or reproducibility of these tests , and studies comparing their sensitivity to therapeutic intervention .
Physiological responses to the 6-min walk test in patients with chronic obstructive pulmonary disease
The 6-min walking test ( 6MWT ) is frequently used to assess functional capacity in chronic cardiopulmonary disorders because of its simplicity . The study examines the physiological responses during encouraged 6MWT in patients with chronic obstructive pulmonary disease . Pulmonary oxygen ( O2 ) uptake ( V′O2 ) was measured in 20 male patients ( age 66±6 yrs , forced expiratory volume in one second 45±14 % predicted ) during 6MWT and incremental cycling  , in r and om order  . O2 tension in arterial blood , carbon dioxide tension in arterial blood and arterial lactate concentration ( [La]art ) were obtained in the last 10 patients . During the 6MWT  , V′O2 showed a plateau after the 3rd min ( 1.39±0.28 , 1.42±0.31 , and 1.40±0.30 L·min−1 , 4th , 5th and 6th min , respectively ) , and minute ventilation ( V′E ) ( 42±8 L·min−1 ) was 91 % maximal voluntary ventilation . No differences were shown between 6MWT ( 6th min ) and peak cycling exercise in V′O2 ( 1.40±0.30 versus 1.41±0.28 L·min−1 , respectively ) , cardiac frequency ( 126±13 versus 130±12 beats·min−1 ) , or arterial respiratory blood gases . The two tests were significantly different in V′E ( 42±8 versus 47±8 L·min−1 , 6MWT versus cycling , respectively ) , carbon dioxide production ( 1.30±0.31 versus 1.45±0.18 L·min−1 ) and [La]art ( 2.9±1.99 versus 5.9±1.51 M ) . The study demonstrates that an encouraged 6-min walking test  generates a high but sustainable oxygen uptake . Since the oxygen uptake plateau reflects the integrated response of the system , it may explain the high prognostic value of the 6-min walking test
Good repeatability ( for the 6MWT and ESWT ) and reproducibility ( for the 6MWT , 12-minute walk test , ISWT , ESWT , and incremental cycle ergometer test ) were reported by most studies assessing these tests , providing patients were familiarized with them beforeh and .
The 6MWT , ISWT , and particularly the ESWT were reported to be sensitive to therapeutic intervention .
Exercise tests are often used to evaluate the functional status of patients with COPD .
However , to the best of our knowledge , a comprehensive systematic comparison of these tests has not been performed .
We systematic ally review ed studies reporting the repeatability and /or reproducibility of these tests , and studies comparing their sensitivity to therapeutic intervention .