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PURPOSE The endurance shuttle walk test (ESWT) was used to evaluate ground-based walking training in chronic obstructive pulmonary disease. During pre-training testing, those who walked 5-10 min on the first ESWT with minimal symptoms performed additional ESWTs at increasing speeds until they were at least moderately symptomatic and terminated the test between 5 and 10 min. This report compares participant characteristics and test responsiveness with participants grouped according to whether or not faster walking speeds were selected for the ESWT during pre-training testing. METHODS We conducted a retrospective analysis of data collected in the intervention group during a randomized controlled trial. The intervention was supervised ground-based walking training, performed two to three times/wk, for 8-10 wk. Prior to and immediately following completion of training, participants completed the 6-min walk test (6MWT), incremental shuttle walk test (ISWT), and ESWT. RESULTS Data were available on 77 participants (70 ± 9 yr, forced expiratory volume in the first second of expiration [FEV1] 43 ± 15 % predicted). For those whom a faster speed was selected during the pre-training ESWTs were characterized by milder dyspnea and leg fatigue on completion of the baseline 6MWT and ISWT (P < .05 for all). On training completion, the change in ESWT was greater in those for whom a faster speed was selected (376 ± 344 sec vs 176 ± 274 sec; P = .017). CONCLUSIONS Participants who report modest symptoms on completion of the pre-training 6MWT or ISWT may achieve a long pre-training ESWT time. In this situation, repeating the pre-training ESWT at a faster walking speed to achieve an exercise time between 5 and 10 min with moderate symptoms may be advantageous.

PURPOSE To determine the reliability, validity, and responsiveness of the incremental shuttle walk test (ISWT) in patients with interstitial lung disease (ILD). METHODS This was a cross-sectional longitudinal study. Patients (n = 27, 10 males; mean age ± SD, 61 ± 9.8 y) with ILD of any etiology, who participated in an outpatient pulmonary rehabilitation (PR) program, were recruited. Reliability was determined by comparing the distance covered in meters between the ISWT-1 and the ISWT-2. Validity was assessed by correlating the distance covered in the ISWT-1, with the maximum oxygen consumption ((Equation is included in full-text article.)O2max) obtained through cardiopulmonary exercise testing and distance covered during the 6-min walk test (6MWT). Responsiveness was assessed by comparing the distance covered in the ISWT-3, undertaken after the completion of PR, to the ISWT-1. RESULTS The distance covered was equivalent between the ISWT-1 (216.7 ± 64.9 m) and the ISWT-2 (220.7 ± 67.3 m), with an excellent intraclass correlation coefficient (ICC2,1 = 0.91; 95% CI, 0.81-0.95). The standard error of measurement and minimal detectable change at the 95% CI (MDC95) values for the ISWT were 19.5 m and 53.9m, respectively. There were significant correlations between the distance covered on the ISWT and (Equation is included in full-text article.)O2max (r = 0.79, P < .0001) and the distance covered on the 6MWT (r = 0.76, P < .0001). Following PR, the change in the ISWT distance showed large effect size (ES = 0.85) and standardized response mean (SRM = 1.58). CONCLUSIONS The ISWT is a reliable, valid, and responsive measure of estimated functional capacity in patients with ILD.

PURPOSE To evaluate the validity of the Incremental Shuttle Walk Test (ISWT) for determining risk stratification in cardiac rehabilitation (CR). METHODS This is a cross-sectional study at a major CR center in a middle-income country. Clinically stable adult cardiac patients underwent an ISWT and an exercise test (ET), wore a pedometer for 7 d, and completed the Godin-Shepherd Leisure-Time Physical Activity Questionnaire. Metabolic equivalents of task (METs) achieved on the ISWT were calculated. RESULTS One hundred fifteen patients were evaluated. The mean ± standard deviation distance on the ISWT was 372.70 ± 128.52 m and METs were 5.03 ± 0.62. The correlation of ISWT distance with ET METs (7.57 ± 2.57), steps/d (4556.71 ± 3280.88), and self-reported exercise (13.08 ± 15.19) was rs = 0.61 (P < .001), rs = 0.37 (P < .001), and rs = 0.20 (P = .031), respectively. Distance on the ISWT accurately predicted METs from the ET (area under the receiver operating characteristic curve = 0.774). The ability to walk ≥410 m on the ISWT predicted, with a specificity of 81.5% and a sensitivity of 65.6%, a functional capacity of ≥7 METs on ET. CONCLUSION The ISWT is an alternative way to evaluate functional capacity in CR and can contribute to the process of identifying patients at low risk for a cardiac event during exercise at moderate intensity.

PURPOSE The 6-Minute Walk Test (6MWT) and Incremental Shuttle Walk Test (ISWT) are used to assess exercise capacity, but the reliability and responsiveness of these tests in individuals with non-cystic fibrosis (CF) bronchiectasis have not been determined. This study aimed to determine the reliability and responsiveness of both tests in adults with non-CF bronchiectasis. METHODS Eighty-five participants completed 2 6MWTs and 2 ISWTs in random order. Testing was repeated at the conclusion of an 8-week intervention period of exercise training. Reliability was assessed using intraclass correlation coefficients (ICC) and Bland-Altman analysis. Responsiveness was measured by effect size (ES) and standardized response mean (SRM). RESULTS At baseline, test-retest reliability was high for both tests (ICC ≥ 0.95). The mean (95% CI) increase in the 6MWT from test 1 to test 2 was 20 m (13-26 m): 3% (0-5%) change. The mean (95% CI) increase in the ISWT was 15 m (4-25m): 4% (2-6%) change. A significant learning effect persisted after 8 weeks for the 6MWT (P = .04), but not the ISWT (P = .61). The 6MWT ES was 0.32 and SRM was 0.68; for the ISWT, ES was 0.42 with SRM of 0.71. CONCLUSION The 6MWT and ISWT are reliable measures of exercise capacity in non-CF bronchiectasis and responsive to exercise training. The small learning effect in both measures at baseline suggests that 2 of each test are necessary to correctly assess exercise capacity. Completion of 2 6MWTs at followup may minimize the risk of underestimating a treatment effect.

PURPOSE: The Incremental Shuttle Walk Test (ISWT) is an important functional and prognostic marker in chronic disease. Aging has a detrimental effect on exercise performance. The objective of this study was to produce normal age-specific values for the ISWT in a healthy British population and to explore whether additional variables improve the accuracy of a predictive equation. METHODS: Healthy subjects (N = 152), aged 40 to 90 years, were recruited. Data collection occurred over 2 study visits. Anthropometric and demographic data were collected, and lung function and quadriceps maximal voluntary contraction were measured. An accelerometer was worn for 2 consecutive days at home. The Duke Activity Status Index was completed, and the greatest distance from 2 ISWTs was recorded. RESULTS: One hundred forty subjects (56 men) with mean age (SD) of 59.4 (11.0) years completed 2 ISWTs. Forced expiratory volume in 1 second (FEV1) was 109.1% (14.56%) predicted and ISWT distance was 737 m (183 m). Age-specific normal values for the ISWT were observed: mean (lower limit of normal)-40 to 49 years, 824 m (765 m); 50 to 59 years, 788 m (730 m); 60 to 69 years, 699 m (649 m); and 70 years and older, 633 m (562 m). A predictive equation was developed from 114 subjects. Age, body mass index, FEV1, quadriceps maximal voluntary contraction, and Duke Activity Status Index contributed to ISWT distance predicting 50.4% of the variation in performance. CONCLUSION: We have developed age-specific normal values for performance on the ISWT in a healthy British population. However, even using practical, clinically relevant variables, it is not possible to accurately predict exercise capacity from a regression equation.