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Cardiopulmonary exercise testing (CPET) is a comprehensive and invaluable assessment used to identify the mechanisms that limit exercise capacity. However, its interpretation remains poorly standardised. This scoping review aims to investigate which limitations to exercise are differentiated by the use of incremental CPET in literature and which criteria are used to identify them. We performed a systematic, electronic literature search of PubMed, Embase, Cochrane CENTRAL, Web of Science and Scopus. All types of publications that reported identification criteria for at least one limitation to exercise based on clinical parameters and CPET variables were eligible for inclusion. 86 publications were included, of which 57 were primary literature and 29 were secondary literature. In general, at the level of the cardiovascular system, a distinction was often made between a normal physiological limitation and a pathological one. Within the respiratory system, ventilatory limitation, commonly identified by a low breathing reserve, and gas exchange limitation, mostly identified by a high minute ventilation/carbon dioxide production slope and/or oxygen desaturation, were often described. Multiple terms were used to describe a limitation in the peripheral muscle, but all variables used to identify this limitation lacked specificity. Deconditioning was a frequently mentioned exercise limiting factor, but there was no consensus on how to identify it through CPET. There is large heterogeneity in the terminology, the classification and the identification criteria of limitations to exercise that are distinguished using incremental CPET. Standardising the interpretation of CPET is essential to establish an objective and consistent framework., Competing Interests: Conflict of interest: I. Gyselinck reports grants from Research Foundation Flanders, and support for attending meetings from AstraZeneca. W. Janssens reports grants from AstraZeneca and Chiesi, consultation fees from AstraZeneca, Chiesi, GSK and Sanofi, payment or honoraria for lectures, presentations, manuscript writing or educational events from AstraZeneca, Chiesi and GSK, support for attending meetings from AstraZeneca and Chiesi, and the following financial (or non-financial) interests: co-founder and chairholder of ARTIQ, a spin-off company of KULeuven. M. Staes, K. Goetschalckx and T. Troosters have nothing to disclose., (Copyright ©The authors 2024.)

Background: Chronic obstructive pulmonary disease (COPD) is associated with a reduced exercise capacity. Although several field tests for exercise capacity have been modified for non-standard settings, i.e. outside the hospital clinic or pulmonary rehabilitation center, their uptake remains limited. Objectives: To assess the test-retest reliability, constuct validity and responsiveness of the one-minute sit-to-stand test (1'STST) adopted in clinical practice among patients with COPD and to confirm the earlier established minimal important difference (MID) of three repetitions. Methods: Patients with COPD performed two 1'STSTs, two 6-minute walk tests (6MWT), an isometric quadriceps force (QF) measurement, a cardiopulmonary exercise test (CPET), and a seven-day physical activity (PA) measurement before and after three months of pulmonary rehabilitation (PR). An Intraclass Correlation Coefficient (ICC) evaluated the agreement between two 1'STSTs. Pearson Correlation examined the association between the 1'STST and other physical measurements, and their changes following PR. A receiver operating characteristic (ROC) curve was constructed using a 30-meter increment in the 6MWT as cut-off to identify responders. Results: The 1'STST demonstrated good reliability (Δ0.9 ± 4.0 repetitions, p = .13; ICC = 0.79). The 1'STST was moderately correlated with the 6MWT (r = 0.57, p < .0001), VO 2 max (r = 0.50, p = .0006) and maximal work rate (r = 0.52, p = .0003). Weak correlations were observed with QF (r = 0.33, p = .03) and step count (r = 0.38, p = .013). The 1'STST improved after PR (∆ = 3.6 ± 6.4 repetitions, p = .0013) and changes correlated moderately with changes in the 6MWT (r = 0.57, p = .002), QF (r = 0.48, p = .003) and VO 2 max (r = 0.41, p = .014). A cut-off of three repetitions demonstrated a 71% accuracy in identifying responders to a rehabilitation program. Conclusion: The 1'STST is a valuable alternative to evaluate exercise capacity in patients with COPD when more expensive and time-consuming tests are unavailable., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: The Daily-PROactive and Clinical visit-PROactive Physical Activity (D-PPAC and C-PPAC) instruments in chronic obstructive pulmonary disease (COPD) combines questionnaire with activity monitor data to measure patients' experience of physical activity. Their amount, difficulty and total scores range from 0 (worst) to 100 (best) but require further psychometric evaluation., Objective: To test reliability, validity and responsiveness, and to define minimal important difference (MID), of the D-PPAC and C-PPAC instruments, in a large population of patients with stable COPD from diverse severities, settings and countries., Methods: We used data from seven randomised controlled trials to evaluate D-PPAC and C-PPAC internal consistency and construct validity by sex, age groups, COPD severity, country and language as well as responsiveness to interventions, ability to detect change and MID., Results: We included 1324 patients (mean (SD) age 66 (8) years, forced expiratory volume in 1 s 55 (17)% predicted). Scores covered almost the full range from 0 to 100, showed strong internal consistency after stratification and correlated as a priori hypothesised with dyspnoea, health-related quality of life and exercise capacity. Difficulty scores improved after pharmacological treatment and pulmonary rehabilitation, while amount scores improved after behavioural physical activity interventions. All scores were responsive to changes in self-reported physical activity experience (both worsening and improvement) and to the occurrence of COPD exacerbations during follow-up. The MID was estimated to 6 for amount and difficulty scores and 4 for total score., Conclusions: The D-PPAC and C-PPAC instruments are reliable and valid across diverse COPD populations and responsive to pharmacological and non-pharmacological interventions and changes in clinically relevant variables., Competing Interests: Competing interests: JG-A reports other from AstraZeneca, other from Esteve, other from Chiesi, other from Menarini, outside the submitted work. SC-R reports personal fees from AstraZeneca, outside the submitted work. DE reports personal fees from Boehringer Ingelheim, outside the submitted work. NI reports personal fees from Almirall, outside the submitted work. NK reports personal fees from AstraZeneca, outside the submitted work. MIP reports personal fees from Philips, grants, personal fees and non-financial support from GSK, during the conduct of the study. MS reports personal fees from Chiesi, outside the submitted work. MT reports personal fees and other from GSK, outside the submitted work. TT reports grants from IMI-JU PROactive grant, during the conduct of the study; other from Boehringer Ingelheim, other from AZ Belgium, outside the submitted work., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Longitudinal data on the effect of time and environmental conditions on physical activity (PA) among COPD patients are currently scarce, but this is an important factor in the design of trials to test interventions that might impact on it. Thus, we aimed to assess the effect of time and climate conditions (temperature, day length and rainfall) on progression of PA in a cohort of COPD patients., Patients and Methods: This is a prospective, multicenter, cohort study undertaken as part of the EU/IMI PROactive project, in which we assessed 236 COPD patients simultaneously wearing two activity monitors (Dynaport MiniMod and Actigraph GT3X). A multivariable generalized linear model analysis was conducted to describe the effect of the explanatory variables on PA measures, over three time points (baseline, 6 and 12 months)., Results: At 12 months (n=157; FEV 1 % predicted=57.7±21.9) there was a significant reduction in all PA measures (Actigraph step count (4284±3533 vs 3533±293)), Actigraph moderate- to vigorous-intensity PA ratio (8.8 (18.8) vs 6.1 (15.7)), Actigraph vector magnitude units (374,902.4 (265,269) vs 336,240 (214,432)), MiniMod walking time (59.1 (34.9) vs 56.9 (38.7) mins) and MiniMod PA intensity (0.183 (0) vs 0.181 (0)). Time had a significant, negative effect on most PA measures in multivariable analysis, after correcting for climate factors, study center, age, FEV 1 % predicted, 6MWD and other disease severity measures. Rainfall was the only climate factor with a negative effect on most PA parameters., Conclusion: COPD patients demonstrate a significant decrease in PA over 1 year follow-up, which is further affected by hours of rainfall, but not by other climate considerations., Competing Interests: JGA received payments for consulting and lecture fees to her Institution from AstraZeneca and lecture fees from Esteeve and Chiesi, outside the submitted work. MIP received personal fees from Phillips, grants from EU and travel expenses from CBQC, outside the submitted work. TvdM is currently a part-time employee of GSK London. The authors report no other conflicts of interest in this work., (© 2019 Boutou et al.)

Physical activity is important to maintain health. Patients who reduce their physical activity are at increased risk of developing comorbidities and faster decline in health. Interventions to enhance physical activity require a behavior change from patients and these interventions have become increasingly popular in chronic obstructive pulmonary disease. However, few interventions have shown long-term effects and all focused on enhancing physical activity rather than the maintenance thereof. In patients with very low exercise tolerance or with significant symptom burden, enhancing physical activity be difficult and interventions should first focus on enhancing exercise tolerance., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: Pulmonary rehabilitation (PR) enhances exercise tolerance in patients with COPD; however, improvements in physical activity (PA) are not guaranteed. This study explored the relationship between baseline exercise tolerance and changes in PA after PR., Materials and Methods: Patient data from prospective clinical trials in the PR settings of Athens and Leuven (2008-2016) were analyzed. Validated PA monitors were worn for 1 week before and after a 12-week program. The proportion of patients who improved PA levels ≥1,000 steps/day ("PA responders") after PR was compared between those with initial 6-minute walk distance [6MWDi] <350 m and ≥350 m. Baseline predictors of PA change were evaluated via univariate and multivariate logistic regression analyses., Results: Two hundred thirty-six patients with COPD (median [IQR] FEV 1 44 [33-59] % predicted, age 65±8 years, 6MWDi 416 [332-486] m) were included. The proportion of "PA responders" after PR was significantly greater in those with higher vs lower 6MWDi (37.9% vs 16.4%, respectively; P <0.001). 6MWDi group classification was the strongest baseline independent predictor of PA improvement (univariate OR 3.10, 95% CI 1.51-6.36)., Conclusion: The likelihood of improving PA after PR is increased with greater 6MWDi. Baseline exercise tolerance appears as an important stratification metric for future research in this field., Competing Interests: Disclosure CRO was the recipient of a European Respiratory Society fellowship, grant number LTRF 2014-3132. ZL was the recipient of a European Respiratory Society Fellowship, grant number LTRF 2016-6686 and is a postdoctoral fellow of the FWO-Flanders (Fellowship number 12U5618N). HD was the recipient of a joint ERS/SEPAR Fellowship (LTRF 2015-5099) and is a postdoctoral research fellow of the FWO-Flanders (12H7517N). FMR was supported by The National Council for Scientific and Technological Development (CNPq), Brazil (249579/2013-8). TT is supported by the Flemish Research Foundation (FondsWetenschappelijk Onderzoek), grant number FWO G·0871·13. The authors report no other conflicts of interest in this work.

Background: Few data are available on the long-term effect of pulmonary rehabilitation (PR) and on long PR programs in interstitial lung diseases (ILD). We aimed to evaluate the effects of PR on exercise capacity (6-Minute Walking Distance, 6MWD; Peak Work Rate, W max ), quality of life (St George's Respiratory Questionnaire, SGRQ), quadriceps force (QF) and objectively measured physical activity in ILD after the 6-month PR-program and after 1 year., Methods: 60 patients (64 ± 11 years; 62% males; 23% with IPF) were randomly assigned to receive a 6 month-PR program or usual medical care., Results: Exercise capacity, quality of life and muscle force increased significantly after the program as compared to control (mean,95%CI[ll to ul]; 6MWD + 72,[36 to 108] m; W max 19, [8 to 29]%pred; SGRQ - 12,[- 19 to - 6] points; QF 10, [1 to 18] %pred). The gain was sustained after 1 year (6MWD 73,[28 to 118] m; Wmax 23, [10 to 35]%pred; SGRQ - 11,[- 18 to - 4] points; QF 9.5, [1 to 18] %pred). Physical activity did not change., Conclusions: PR improves exercise tolerance, health status and muscle force in ILD. The benefits are maintained at 1-year follow-up. The intervention did not change physical activity., Trial Registration: Clinicaltrials.gov NCT00882817 .

The Phase IV, 8-week, randomized, double-blind, placebo-controlled ACTIVATE study (NCT02424344) evaluated the effect of aclidinium/formoterol (AB/FF) 400/12 μg twice daily on lung hyperinflation, exercise capacity, and physical activity in patients with moderate-to-severe COPD. Patients received AB/FF (n=134) or placebo (n=133) (1:1) via the Genuair™/Pressair ® dry powder inhaler for 8 weeks. From Weeks 5 to 8, all patients participated in behavioral intervention (BI; daily messages providing step goals). The primary end point was trough functional residual capacity (FRC) at Week 4. Exercise endurance time and physical activity were assessed at Week 4 (pharmacotherapy only) and at Week 8 (8 weeks of pharmacotherapy plus 4 weeks of BI). Other end points included post-dose FRC, residual volume, and inspiratory capacity (IC) at rest and during exercise. After 4 weeks, trough FRC improved with AB/FF versus placebo but did not reach significance (125 mL; P =0.0690). However, post-dose FRC, residual volume, and IC at rest improved significantly with AB/FF at Week 4 versus placebo (all P <0.0001). AB/FF significantly improved exercise endurance time and IC at isotime versus placebo at Week 4 ( P <0.01 and P <0.0001, respectively) and Week 8 ( P <0.05 and P <0.0001, respectively). AB/FF achieved higher step counts ( P <0.01) with fewer inactive patients ( P <0.0001) at Week 4 versus placebo. Following BI, AB/FF maintained improvements in physical activity at Week 8 and nonsignificant improvements were observed with placebo. AB/FF 400/12 μg demonstrated improvements in lung hyperinflation, exercise capacity, and physical activity versus placebo that were maintained following the addition of BI. A 4-week period of BI might be too short to augment the improvements of physical activity observed with AB/FF., Competing Interests: Disclosure Henrik Watz has received honoraria for consultancies, lectures, and travel support to attend scientific congresses from Almirall, AstraZeneca, Berlin-Chemie, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Novartis, and Takeda. His institution received investigator fees for participation in clinical trials from Almirall, AstraZeneca, Bayer Health Care, Berlin-Chemie, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Novartis, Sanofi Aventis, Roche, and Takeda. Thierry Troosters has received grants from the Innovative Medicines Initiative Joint Undertaking and speaker fees from Boehringer Ingelheim, AstraZeneca, and GlaxoSmithKline. Kai M Beeh’s institution has received compensation for organizing or participating in advisory boards (from Almirall Hermal, Cytos, Chiesi, Boehringer Ingelheim, AstraZeneca, Mundipharma, Novartis, and Teva), has participated in scientific meetings or courses (supported by Almirall Hermal, AstraZeneca, Boehringer Ingelheim, Mundipharma, Novartis, Pfizer, and Teva) in the past 3 years, has received consulting fees (from Ablynx, Apellis Pharmaceuticals, Sterna GmbH, Chiesi, and Cytos), and has received compensation for the design, performance, or participation in single or multicenter clinical trials in the past 3 years (from Almirall, AstraZeneca, Boehringer Ingelheim, GlaxoSmith-Kline, Infinity, Mundipharma, Novartis, Pfizer, Revotar Biopharmaceuticals, Sterna GmbH, Teva, and Zentiva). Judith Garcia-Aymerich’s institution has received consulting and lecture fees from AstraZeneca, and lecture fees from Esteve. Pierluigi Paggiaro is on the AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, and Novartis boards and has received lecture fees from AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Laboratori Guidotti, Menarini, Mundipharma, Novartis, Sanofi, and Teva. Eduard Molins, Diana Jarreta, and Esther Garcia Gil are employees of AstraZeneca PLC, Barcelona, Spain. Massimo Notari is an employee of A. Menarini Farmaceutica Internazionale S.R.L., Firenze, Italy. Antonio Zapata is an employee of Laboratorios Menarini, S.A., Badalona, Spain. The authors report no other conflicts of interest in this work.

Background: Guidelines have provided positive recommendations for pulmonary rehabilitation after exacerbations of chronic obstructive pulmonary disease (COPD), but recent studies indicate that postexacerbation rehabilitation may not always be effective in patients with unstable COPD., Objectives: To assess effects of pulmonary rehabilitation after COPD exacerbations on hospital admissions (primary outcome) and other patient-important outcomes (mortality, health-related quality of life (HRQL) and exercise capacity)., Search Methods: We identified studies through searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PEDro (Physiotherapy Evidence Database) and the Cochrane Airways Review Group Register of Trials. Searches were current as of 20 October 2015, and handsearches were run up to 5 April 2016., Selection Criteria: Randomised controlled trials (RCTs) comparing pulmonary rehabilitation of any duration after exacerbation of COPD versus conventional care. Pulmonary rehabilitation programmes had to include at least physical exercise (endurance or strength exercise, or both). We did not apply a criterion for the minimum number of exercise sessions a rehabilitation programme had to offer to be included in the review. Control groups received conventional community care without rehabilitation., Data Collection and Analysis: We expected substantial heterogeneity across trials in terms of how extensive rehabilitation programmes were (i.e. in terms of number of completed exercise sessions; type, intensity and supervision of exercise training; and patient education), duration of follow-up (< 3 months vs ≥ 3 months) and risk of bias (generation of random sequence, concealment of random allocation and blinding); therefore, we performed subgroup analyses that were defined before we carried them out. We used standard methods expected by Cochrane in preparing this update, and we used GRADE for assessing the quality of evidence., Main Results: For this update, we added 11 studies and included a total of 20 studies (1477 participants). Rehabilitation programmes showed great diversity in terms of exercise training (number of completed exercise sessions; type, intensity and supervision), patient education (from none to extensive self-management programmes) and how they were organised (within one setting, e.g. pulmonary rehabilitation, to across several settings, e.g. hospital, outpatient centre and home). In eight studies, participants completed extensive pulmonary rehabilitation, and in 12 studies, participants completed pulmonary rehabilitation ranging from not extensive to moderately extensive.Eight studies involving 810 participants contributed data on hospital readmissions. Moderate-quality evidence indicates that pulmonary rehabilitation reduced hospital readmissions (pooled odds ratio (OR) 0.44, 95% confidence interval (CI) 0.21 to 0.91), but results were heterogenous (I 2 = 77%). Extensiveness of rehabilitation programmes and risk of bias may offer an explanation for the heterogeneity, but subgroup analyses were not statistically significant (P values for subgroup effects were between 0.07 and 0.11). Six studies including 670 participants contributed data on mortality. The quality of evidence was low, and the meta-analysis did not show a statistically significant effect of rehabilitation on mortality (pooled OR 0.68, 95% CI 0.28 to 1.67). Again, results were heterogenous (I 2 = 59%). Subgroup analyses showed statistically significant differences in subgroup effects between trials with more and less extensive rehabilitation programmes and between trials at low and high risk for bias, indicating possible explanations for the heterogeneity. Hospital readmissions and mortality studies newly included in this update showed, on average, significantly smaller effects of rehabilitation than were seen in earlier studies.High-quality evidence suggests that pulmonary rehabilitation after an exacerbation improves health-related quality of life. The eight studies that used St George's Respiratory Questionnaire (SGRQ) reported a statistically significant effect on SGRQ total score, which was above the minimal important difference (MID) of four points (mean difference (MD) -7.80, 95% CI -12.12 to -3.47; I 2 = 64%). Investigators also noted statistically significant and important effects (greater than MID) for the impact and activities domains of the SGRQ. Effects were not statistically significant for the SGRQ symptoms domain. Again, all of these analyses showed heterogeneity, but most studies showed positive effects of pulmonary rehabilitation, some studies showed large effects and others smaller but statistically significant effects. Trials at high risk of bias because of lack of concealment of random allocation showed statistically significantly larger effects on the SGRQ than trials at low risk of bias. High-quality evidence shows that six-minute walk distance (6MWD) improved, on average, by 62 meters (95% CI 38 to 86; I 2 = 87%). Heterogeneity was driven particularly by differences between studies showing very large effects and studies showing smaller but statistically significant effects. For both health-related quality of life and exercise capacity, studies newly included in this update showed, on average, smaller effects of rehabilitation than were seen in earlier studies, but the overall results of this review have not changed to an important extent compared with results reported in the earlier version of this review.Five studies involving 278 participants explicitly recorded adverse events, four studies reported no adverse events during rehabilitation programmes and one study reported one serious event., Authors' Conclusions: Overall, evidence of high quality shows moderate to large effects of rehabilitation on health-related quality of life and exercise capacity in patients with COPD after an exacerbation. Some recent studies showed no benefit of rehabilitation on hospital readmissions and mortality and introduced heterogeneity as compared with the last update of this review. Such heterogeneity of effects on hospital readmissions and mortality may be explained to some extent by the extensiveness of rehabilitation programmes and by the methodological quality of the included studies. Future researchers must investigate how the extent of rehabilitation programmes in terms of exercise sessions, self-management education and other components affects the outcomes, and how the organisation of such programmes within specific healthcare systems determines their effects after COPD exacerbations on hospital readmissions and mortality.

The impact of rehabilitation-induced changes in 6-minute walk distance (6MWD) on the survival of patients with chronic obstructive pulmonary disease (COPD) has not been fully elucidated. This study sought to determine the association of baseline 6MWD and its changes after pulmonary rehabilitation (PR) with 5-year survival in patients with COPD. Patients who were referred to a 12-week outpatient PR program were followed up for 5 years postcompletion, and survival status was verified. Survival was analyzed according to four groups based upon initial 6MWD (6MWDi) and its changes (Δ6MWD) after PR (Group 1: 6MWDi ≥350 m and Δ6MWD ≥30 m; Group 2: 6MWDi ≥350 m and Δ6MWD <30 m; Group 3: 6MWDi <350 m and Δ6MWD ≥30 m; and Group 4: 6MWDi <350 m and Δ6MWD <30 m) via Kaplan-Meier analysis and log rank test. Cox regression was performed to identify possible confounders of mortality estimates. In total, 423 patients (with mean ± standard deviation of forced expiratory volume in the first second [FEV 1 ] 43±16% predicted, age 65±8 years, and 6WMDi 381±134 m) underwent PR between 1999 and 2010. Survival rates decreased progressively from Group 1 to Group 4 (Group 1, 81%; Group 2, 69%; Group 3, 47%; Group 4, 27%; log rank test, P <0.05). 6MWDi ≥350 m (hazard ratio [HR] 0.39 [95% confidence interval {CI} 0.30-0.50]) and Δ6MWD ≥30 m (HR 0.66 [95% CI 0.51-0.85]) were strongly and independently associated with survival. Compared with Group 1, mortality risks progressively increased in Group 2 (HR 1.36 [95% CI 0.92-2.00]; not significant), Group 3 (HR 1.90 [95% CI 1.28-2.84]; P =0.001), and Group 4 (HR 3.28 [95% CI 2.02-5.33]; P <0.0001). Both poor 6MWD and lack of improvement >30 m after PR are associated with worse 5-year survival in patients with COPD., Competing Interests: The authors report no conflicts of interest in this work.

Background: Changes in physical activity (PA) are difficult to interpret because no framework of minimal important difference (MID) exists. We aimed to determine the minimal important difference (MID) in physical activity (PA) in patients with Chronic Obstructive Pulmonary Disease and to clinically validate this MID by evaluating its impact on time to first COPD-related hospitalization., Methods: PA was objectively measured for one week in 74 patients before and after three months of rehabilitation (rehabilitation sample). In addition the intraclass correlation coefficient was measured in 30 patients (test-retest sample), by measuring PA for two consecutive weeks. Daily number of steps was chosen as outcome measurement. Different distribution and anchor based methods were chosen to calculate the MID. Time to first hospitalization due to an exacerbation was compared between patients exceeding the MID and those who did not., Results: Calculation of the MID resulted in 599 (Standard Error of Measurement), 1029 (empirical rule effect size), 1072 (Cohen's effect size) and 1131 (0.5SD) steps.day-1. An anchor based estimation could not be obtained because of the lack of a sufficiently related anchor. The time to the first hospital admission was significantly different between patients exceeding the MID and patients who did not, using the Standard Error of Measurement as cutoff., Conclusions: The MID after pulmonary rehabilitation lies between 600 and 1100 steps.day-1. The clinical importance of this change is supported by a reduced risk for hospital admission in those patients with more than 600 steps improvement.

Introduction: Chronic obstructive pulmonary disease (COPD) is associated with exercise limitation and physical inactivity, which are believed to have significant long-term negative health consequences for patients. While a number of COPD treatments and exercise training programmes increase exercise capacity, there is limited evidence for their effects on physical activity levels, with no clear association between exercise capacity and physical activity in clinical trials. Physical activity depends on a number of behaviour, environmental and physiological factors. We describe the design of the PHYSACTO trial, which is investigating the effects of bronchodilators, either alone or with exercise training, in combination with a standardised behaviour-change self-management programme, on exercise capacity and physical activity in patients with COPD. It is hypothesised that bronchodilators in conjunction with a behaviour-change self-management programme will improve physical activity and that this effect will be amplified by the addition of exercise training., Methods and Analysis: Patients are being recruited from 34 sites in Australia, New Zealand, the USA, Canada and Europe. Patients receiving a multicomponent intervention designed to support behaviour change related to physical activity are randomised to four treatment arms: placebo, tiotropium, tiotropium+olodaterol, and tiotropium+olodaterol+exercise training. The primary outcome is improvement in exercise capacity after 8 weeks, measured by endurance time during a shuttle walk test. The secondary outcome is improvement in physical activity, including objective accelerometer assessment and patient-reported functioning using the Functional Performance Inventory-Short Form and the novel hybrid PROactive instrument. Additionally, the influence of moderating variables (ie, factors influencing a patient's choice to be physically active) on increases in physical activity is also explored., Ethics and Dissemination: The study has been approved by the relevant Institutional Review Boards, Independent Ethics Committee and Competent Authority according to national and international regulations. The findings of the trial will be disseminated through relevant peer-reviewed journals and international conference presentations., Trial Registration Number: NCT02085161., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

This document reviews 1) the measurement properties of commonly used exercise tests in patients with chronic respiratory diseases and 2) published studies on their utilty and/or evaluation obtained from MEDLINE and Cochrane Library searches between 1990 and March 2015.Exercise tests are reliable and consistently responsive to rehabilitative and pharmacological interventions. Thresholds for clinically important changes in performance are available for several tests. In pulmonary arterial hypertension, the 6-min walk test (6MWT), peak oxygen uptake and ventilation/carbon dioxide output indices appear to be the variables most responsive to vasodilators. While bronchodilators do not always show clinically relevant effects in chronic obstructive pulmonary disease, high-intensity constant work-rate (endurance) tests (CWRET) are considerably more responsive than incremental exercise tests and 6MWTs. High-intensity CWRETs need to be standardised to reduce interindividual variability. Additional physiological information and responsiveness can be obtained from isotime measurements, particularly of inspiratory capacity and dyspnoea. Less evidence is available for the endurance shuttle walk test. Although the incremental shuttle walk test and 6MWT are reliable and less expensive than cardiopulmonary exercise testing, two repetitions are needed at baseline. All exercise tests are safe when recommended precautions are followed, with evidence suggesting that no test is safer than others., (Copyright ©ERS 2016.)

Background: Non-malignant dust-related respiratory diseases, such as asbestosis and silicosis, are similar to other chronic respiratory diseases and may be characterised by breathlessness, reduced exercise capacity and reduced health-related quality of life. Some non-malignant dust-related respiratory diseases are a global health issue and very few treatment options, including pharmacological, are available. Therefore, examining the role of exercise training is particularly important to determine whether exercise training is an effective treatment option in non-malignant dust-related respiratory diseases., Objectives: To assess the effects of exercise training for people with non-malignant dust-related respiratory diseases compared with control, placebo or another non-exercise intervention on exercise capacity, health-related quality of life and levels of physical activity., Search Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE/PubMed, EMBASE, CINAHL, PEDro and AMED (all searched from inception until February 2015), national and international clinical trial registries, reference lists of relevant papers and we contacted experts in the field for identification of suitable studies., Selection Criteria: We included only randomised controlled trials (RCTs) that compared exercise training of at least four weeks duration with no exercise training, placebo or another non-exercise intervention., Data Collection and Analysis: We used standard methodological procedures expected by Cochrane. Two review authors independently assessed study eligibility and risk of bias, and extracted data. We employed the GRADE approach to assess the overall quality of evidence for each outcome and to interpret findings. We synthesized study results using a random-effects model based on the assessment of heterogeneity. We conducted subgroup analyses on participants with dust-related interstitial lung diseases (ILDs) and participants with asbestos related pleural disease (ARPD)., Main Results: Two RCTs including a combined total of 40 participants (35 from one study and five from a second study) met the inclusion criteria. Twenty-one participants were randomised to the exercise training group and 19 participants were randomised to the control group. The included studies evaluated the effects of exercise training compared to a control group of no exercise training in people with dust-related ILDs and ARPD. The exercise training programme in both studies was in an outpatient setting for an eight-week period. The risk of bias was low in both studies. There were no reported adverse events of exercise training. Following exercise training, six-minute walk distance (6MWD) increased with a mean difference (MD) of 53.81 metres (m) (95% CI 34.36 to 73.26 m). Improvements were also seen in the domains of health-related quality of life: Chronic Respiratory Disease Questionnaire (CRQ) Dyspnoea domain (MD 2.58, 95% CI 0.72 to 4.44); CRQ Fatigue domain (MD 1.00, 95% CI 0.11 to 1.89); CRQ Emotional Function domain (MD 2.61, 95% CI 0.74 to 4.49); and CRQ Mastery domain (MD 1.51, 95% CI 0.29 to 2.72). Improvements in exercise capacity and health-related quality of life were also evident six months following the intervention period: 6MWD (MD 52.68 m, 95% CI 27.43 to 77.93 m); CRQ Dyspnoea domain (MD 3.03, 95% CI 1.41 to 4.66); CRQ Emotional Function domain (MD 5.57, 95% CI 2.34 to 8.81); and CRQ Mastery domain (MD 2.66, 95% CI 1.08 to 4.23). Exercise training did not result in improvements in the Modified Medical Research Council (MMRC) dyspnoea scale immediately following exercise training or six months following exercise training. The improvements following exercise training were similar in a subgroup of participants with dust-related ILDs and in a subgroup of participants with ARPD compared to the control group, with no statistically significant differences in treatment effects between the subgroups., Authors' Conclusions: The evidence examining exercise training in people with non-malignant dust-related respiratory diseases is of very low quality. This is due to imprecision in the results from the small number of trials and the small number of participants, the indirectness of evidence due to a paucity of information on disease severity and the data from one study being from a subgroup of participants, and inconsistency from high heterogeneity in some results. Therefore, although the review findings indicate that an exercise training programme is effective in improving exercise capacity and health-related quality of life in the short-term and at six months follow-up, we remain unsure of these findings due to the very low quality evidence. Larger, high quality trials are needed to determine the strength of these findings.

Background: In some patients with COPD, the disease is characterized by exacerbations. Severe exacerbations warrant a hospitalization, with prolonged detrimental effects on physical activity. Interventions after an exacerbation may improve physical activity, with longstanding health benefits. Physical activity counseling and real-time feedback were effective in stable COPD. No evidence is available on the use of this therapeutic modality in patients after a COPD exacerbation., Methods: Thirty patients were randomly assigned to usual care or physical activity counseling, by telephone contacts at a frequency of 3 times a week and real-time feedback. Lung function, peripheral muscle strength, functional exercise capacity, symptom experience and COPD-related health status were assessed during hospital stay and 1 month later., Results: Both groups significantly recovered in physical activity (PAsteps: control group: 1013 ± 1275 steps vs intervention group: 984 ± 1208 steps (p = 0.0005); PAwalk: control group: 13 ± 14 min vs intervention group: 13 ± 16 min (p = 0.0002)), functional exercise capacity (control group: 64 ± 59 m (p = 0.002) vs intervention group: 67 ± 84 m (p = 0.02)) and COPD-related health status (CAT: control group: -5 [-7 to 1] (p = 0.02) vs intervention group: -3 [-10 to 1] points (p = 0.03)). No differences between groups were observed., Conclusion: From our pilot study, we concluded that telephone based physical activity counseling with pedometer feedback after an exacerbation did not result in better improvements in physical activity and clinical outcomes compared to usual care. Because of the difficult recruitment and the negative intermediate analyses, this study was not continued., Trial Registration: Clinicaltrials.gov NCT02223962. Registered 4 September 2013.

Background: There is a wide variability in measurement methodology of physical activity. This study investigated the effect of different analysis techniques on the statistical power of physical activity outcomes after pulmonary rehabilitation., Methods: Physical activity was measured with an activity monitor armband in 57 patients with COPD (mean ± SD age, 66 ± 7 years; FEV1, 46 ± 17% predicted) before and after 3 months of pulmonary rehabilitation. The choice of the outcome (daily number of steps [STEPS], time spent in at least moderate physical activity [TMA], mean metabolic equivalents of task level [METS], and activity time [ACT]), impact of weekends, number of days of assessment, postprocessing techniques, and influence of duration of daylight time (DT) on the sample size to achieve a power of 0.8 were investigated., Results: The STEPS and ACT (1.6-2.3 metabolic equivalents of task) were the most sensitive outcomes. Excluding weekends decreased the sample size for STEPS (83 vs 56), TMA (160 vs 148), and METS (251 vs 207). Using 4 weekdays (STEPS and TMA) or 5 weekdays (METS) rendered the lowest sample size. Excluding days with < 8 h wearing time reduced the sample size for STEPS (56 vs 51). Differences in DT were an important confounder., Conclusions: Changes in physical activity following pulmonary rehabilitation are best measured for 4 weekdays, including only days with at least 8 h of wearing time (during waking hours) and considering the difference in DT as a covariate in the analysis., Trial Registry: ClinicalTrials.gov; No.: NCT00948623; URL: www.clinicaltrials.gov.

Background: Limb muscle dysfunction is prevalent in chronic obstructive pulmonary disease (COPD) and it has important clinical implications, such as reduced exercise tolerance, quality of life, and even survival. Since the previous American Thoracic Society/European Respiratory Society (ATS/ERS) statement on limb muscle dysfunction, important progress has been made on the characterization of this problem and on our understanding of its pathophysiology and clinical implications., Purpose: The purpose of this document is to update the 1999 ATS/ERS statement on limb muscle dysfunction in COPD., Methods: An interdisciplinary committee of experts from the ATS and ERS Pulmonary Rehabilitation and Clinical Problems assemblies determined that the scope of this document should be limited to limb muscles. Committee members conducted focused reviews of the literature on several topics. A librarian also performed a literature search. An ATS methodologist provided advice to the committee, ensuring that the methodological approach was consistent with ATS standards., Results: We identified important advances in our understanding of the extent and nature of the structural alterations in limb muscles in patients with COPD. Since the last update, landmark studies were published on the mechanisms of development of limb muscle dysfunction in COPD and on the treatment of this condition. We now have a better understanding of the clinical implications of limb muscle dysfunction. Although exercise training is the most potent intervention to address this condition, other therapies, such as neuromuscular electrical stimulation, are emerging. Assessment of limb muscle function can identify patients who are at increased risk of poor clinical outcomes, such as exercise intolerance and premature mortality., Conclusions: Limb muscle dysfunction is a key systemic consequence of COPD. However, there are still important gaps in our knowledge about the mechanisms of development of this problem. Strategies for early detection and specific treatments for this condition are also needed.

Chronic obstructive pulmonary disease (COPD) is a debilitating disease affecting patients in daily life, both physically and emotionally. Symptoms such as dyspnea and muscle fatigue, lead to exercise intolerance, which, together with behavioral issues, trigger physical inactivity, a key feature of COPD. Physical inactivity is associated with adverse clinical outcomes, including hospitalization and all-cause mortality. Increasing activity levels is crucial for effective management strategies and could lead to improved long-term outcomes. In this review we summarize objective and subjective instruments for evaluating physical activity and focus on interventions such as pulmonary rehabilitation or bronchodilators aimed at increasing activity levels. To date, only limited evidence exists to support the effectiveness of these interventions. We suggest that a multimodal approach comprising pulmonary rehabilitation, pharmacotherapy, and counselling programs aimed at addressing emotional and behavioural aspects of COPD may be an effective way to increase physical activity and improve health status in the long term.

Background: Adult patients with cystic fibrosis have peripheral muscle weakness, which is related to exercise intolerance and poor prognosis. The influence of acute exacerbations on muscle strength has been poorly studied. This study aimed to investigate whether quadriceps force (QF), as assessed with an involuntary technique, changes during intravenous antibiotics therapy (IVAT) for an exacerbation., Methods: QF was measured in 20 patients using twitch stimulation of the femoral nerve at the day of hospitalization (day 1) and at termination (day 14) of the IVAT. Physical activity was monitored during IVAT using a SenseWear armband. Ten stable patients served as control subjects., Results: QF did not change during exacerbation (potentiated twitch force at day 1: 140 ± 42 N, at day 14: 140 ± 47 N), but a decrease was observed in individual patients. Changes in twitch force during exacerbation were correlated with time spent in activities of at least moderate intensity (r = 0.61, p = 0.007)., Conclusions: QF does not systematically decrease during exacerbations of cystic fibrosis. Individual changes in QF are well correlated with daily time spent in activities of at least moderate intensity.

Background: Pulmonary rehabilitation has become a cornerstone in the management of patients with stable Chronic Obstructive Pulmonary Disease (COPD). Systematic reviews have shown large and important clinical effects of pulmonary rehabilitation in these patients. However, in unstable COPD patients who have recently suffered an exacerbation, the effects of pulmonary rehabilitation are less established., Objectives: To assess the effects of pulmonary rehabilitation after COPD exacerbations on future hospital admissions (primary outcome) and other patient-important outcomes (mortality, health-related quality of life and exercise capacity)., Search Strategy: Trials were identified from searches of CENTRAL, MEDLINE, EMBASE, PEDRO and the Cochrane Airways Group Register of Trials. Searches were current as of March 2010., Selection Criteria: Randomized controlled trials comparing pulmonary rehabilitation of any duration after exacerbation of COPD with conventional care. Pulmonary rehabilitation programmes needed to include at least physical exercise. Control groups received conventional community care without rehabilitation., Data Collection and Analysis: We calculated pooled odds ratios and weighted mean differences (MD) using random-effects models. We requested missing data from the authors of the primary studies., Main Results: We identified nine trials involving 432 patients. Pulmonary rehabilitation significantly reduced hospital admissions (pooled odds ratio 0.22 [95% CI 0.08 to 0.58], number needed to treat (NNT) 4 [95% CI 3 to 8], over 25 weeks) and mortality (OR 0.28; 95% CI 0.10 to 0.84), NNT 6 [95% CI 5 to 30] over 107 weeks). Effects of pulmonary rehabilitation on health-related quality of life were well above the minimal important difference when measured by the Chronic Respiratory Questionnaire (MD for dyspnea, fatigue, emotional function and mastery domains between 0.81 (fatigue; 95% CI 0.16 to 1.45) and 0.97 (dyspnea; 95% CI 0.35 to 1.58)) and the St. Georges Respiratory Questionnaire total score (MD -9.88; 95% CI -14.40 to -5.37); impacts domain (MD -13.94; 95% CI -20.37 to -7.51) and for activity limitation domain (MD -9.94; 95% CI -15.98 to -3.89)). The symptoms domain of the St. Georges Respiratory Questionnaire showed no significant improvement. Pulmonary rehabilitation significantly improved exercise capacity and the improvement was above the minimally important difference (six-minute walk test (MD 77.70 meters; 95% CI 12.21 to 143.20) and shuttle walk test (MD 64.35; 95% CI 41.28 to 87.43)). No adverse events were reported in three studies., Authors' Conclusions: Evidence from nine small studies of moderate methodological quality, suggests that pulmonary rehabilitation is a highly effective and safe intervention to reduce hospital admissions and mortality and to improve health-related quality of life in COPD patients who have recently suffered an exacerbation of COPD.

Background: Pulmonary rehabilitation programs improve exercise tolerance, muscle strength, and dyspnea in patients with COPD. The aim of the study was to assess prospectively the effectiveness and feasibility of pulmonary rehabilitation in patients with restrictive lung diseases., Methods: In a prospective, nonrandomized, noncontrolled study, patients with an established diagnosis of restrictive lung disease (RLD) participated in a 24-week outpatient multidisciplinary rehabilitation program. Pulmonary function, exercise capacity, muscle force, and dyspnea were measured at inclusion, after 12 and 24 weeks of rehabilitation. Primary outcome was the change in 6-min walk distance (6MWD) after 12 weeks of rehabilitation., Results: Twenty-nine patients out of 31 patients (57 +/- 17 years of age; 21 men; FEV(1): 1.4 +/- 0.7 L) completed the 12-week rehabilitation program and 26 patients the 24-week rehabilitation program. At inclusion, exercise tolerance (maximal oxygen consumption [V(O(2))max]: 63% +/- 27% predicted; 6MWD: 390 +/- 140 m) and quadriceps force ([QF] 61% +/- 21% predicted) were reduced, and dyspnea, assessed using the Chronic Respiratory Disease Questionnaire (CRDQ), was increased (CRDQ item dyspnea [CRDQd]: 16 +/- 6 points). Exercise capacity, muscle force, and CRDQd improved significantly after 12 weeks (6MWD: 445 +/- 142 m; V(O(2))max: 69% +/- 30% predicted; QF: 73% +/- 25% predicted; CRDQd: 20 +/- 6 points) (P < .05). Further improvements were noted after 24 weeks (6MWD: 463 +/- 146 m; CRDQd: 22 +/- 6 points)., Conclusions: Patients with RLD respond well after 12 weeks of pulmonary rehabilitation, and even better results were seen after 24 weeks. Clinically significant improvements were obtained in the majority of the patients after 24 weeks.

Background: Pulmonary rehabilitation has become a cornerstone in the management of patients with stable Chronic Obstructive Pulmonary Disease (COPD). Systematic reviews have shown large and important clinical effects of pulmonary rehabilitation in these patients. In unstable COPD patients who have suffered from an exacerbation recently, however, the effects of pulmonary rehabilitation are less established., Objectives: To assess the effects of pulmonary rehabilitation after COPD exacerbations on future hospital admissions (primary outcome) and other patient-important outcomes (mortality, health-related quality of life and exercise capacity)., Search Strategy: Trials were identified from searches of CENTRAL, MEDLINE, EMBASE, PEDRO and the Cochrane Central Register of Controlled Trials. Searches were current as of July 2008., Selection Criteria: Randomized controlled trials comparing pulmonary rehabilitation of any duration after exacerbation of COPD with conventional care. Pulmonary rehabilitation programmes needed to include at least physical exercise. Control groups received conventional community care without rehabilitation., Data Collection and Analysis: We calculated pooled odds ratios and weighted mean differences (WMD) using fixed-effects models. We requested missing data from the authors of the primary studies., Main Results: We identified six trials including 219 patients. Pulmonary rehabilitation significantly reduced hospital admissions (pooled odds ratio 0.13 [95% CI 0.04 to 0.35], number needed to treat (NNT) 3 [95% CI 2 to 4], over 34 weeks) and mortality (pooled odds ratio 0.29 [95% CI 0.10 to 0.84], NNT 6 [95% CI 5 to 30] over 107 weeks). Effects of pulmonary rehabilitation on health-related quality of life were well above the minimal important difference (weighted mean differences for dyspnea, fatigue, emotional function and mastery domains of the Chronic Respiratory Questionnaire between 1.15 (95% CI: 0.94, 1.36) and 1.88 (95% CI:1.67, 2.09) and between -9.9 (95% CI:-18.05, -1.73) and -17.1 (95% CI: -23.55, -10.68) for total, impact and activity limitation domains of the St. Georges Respiratory Questionnaire). In all trials, pulmonary rehabilitation improved exercise capacity (60-215 meters in six-minute or shuttle walk tests). No adverse events were reported (two studies)., Authors' Conclusions: Evidence from small studies of moderate methodological quality suggests that pulmonary rehabilitation is a highly effective and safe intervention to reduce hospital admissions and mortality and to improve health-related quality of life in COPD patients after suffering an exacerbation.

The aim of the present study was to investigate the prevalence of muscle weakness and the importance of physical inactivity in cystic fibrosis (CF), and its relationship to exercise tolerance and muscle strength. Exercise tolerance, skeletal and respiratory muscle strength were studied in a group of 64 adults with CF (age 26+/-8 yrs, FEV(1 % predicted) 65+/-19) and in 20 age-matched controls. Physical activity (PA) was assessed in 20 patients and all controls. Quadriceps muscle weakness was present in 56% of the patients. Peak oxygen uptake and 6-min walking distance were below normal in 89 and 75% of patients, respectively. Respiratory muscle strength was normal. The differences remained after correcting for PA. Quadriceps force was correlated to the 6-min walking distance but not to peak oxygen uptake. "Mild" PA (>3 metabolic equivalents (METS)) and the number of steps overlapped with controls, but CF patients had less moderate PA (>4.8 METS). Moderate PA was related to peak oxygen uptake and quadriceps force. Skeletal muscle weakness and exercise intolerance are prevalent in cystic fibrosis. Physical inactivity is a factor significantly contributing to exercise tolerance and skeletal muscle force in adults with cystic fibrosis, but these impairments are in excess to that expected from physical inactivity only.

We investigated the impact of lung transplantation and outpatient pulmonary rehabilitation after lung transplantation on skeletal muscle function and exercise tolerance. Skeletal muscle force (Quadriceps force, QF), exercise tolerance (six minute walking distance, 6MWD) and lung function were assessed in 36 patients before and after lung transplantation. Seventeen male and 19 female patients (age 57 +/- 4) showed skeletal muscle weakness before the transplantation. A further 32 +/- 21% reduction was seen 1.2 (interquartile range 0.9 to 2.0) months after LTX. The number of days on the intensive care unit was significantly related to the observed deterioration in muscle force after LTX. At this time point 6MWD was comparable to pre-LTX. Rehabilitation started 37 (IQR 29 to 61) days after LTX. 6MWD and QF improved significantly (140 +/- 91 m, and 35 +/- 48%, respectively; p < 0.05) with rehabilitation. QF remained below pre-LTX values. The evolution of the 6MWD with the transplantation and the subsequent rehabilitation was less in female compared to male subjects. We conclude that muscle strength deteriorates after lung transplantation, particularly in patients with long ICU stay. Outpatient pulmonary rehabilitation is feasible after lung transplantation and leads to recovery of skeletal muscle function. In female patients this recovery is significantly less compared to male recipients.

Study Objectives: To explore the acute systemic inflammatory and anabolic effects of cycling in hospital admitted patients with chronic obstructive pulmonary disease (COPD) and in patients with clinically stable disease., Design: Cross-sectional comparative study., Setting: University Hospital Gasthuisberg, a tertiary care setting., Patients: 16 patients with clinically stable COPD (no acute exacerbation in the past 12 weeks; median age: 73 years (IQR: 60 to 75); median forced expiratory volume in the first second (FEV1): 45% predicted (IQR: 33 to 58)) and 14 patients who were admitted to a hospital due to an acute exacerbation of COPD (median age: 65 years (IQR: 59 to 74); median FEV1 on day 8 of hospital stay: 41% predicted (IQR: 33 to 54))., Interventions: None., Measurements and Results: Circulating levels of C reactive protein, interleukin 6, interleukin 8 and insulin-like growth factor I were determined before, at the end and 2 and 30 minutes after a symptom-limited peak cycling test and before, at the end and 2 and 30 minutes after a symptom-limited constant-work-rate cycling test at 70% of the peak load. Non-significant changes in the circulating markers of inflammation and anabolism were found during or up to 30 minutes after ceasing the peak or constant-work-rate cycling exercise tests. The systemic responses of the hospitalized patients with COPD did not differ from those with clinically stable disease., Conclusions: High-intensity cycling exercises did not increase the circulating levels of inflammatory markers in patients with chronic obstructive pulmonary disease, irrespective of their clinical stability.

Regular aerobic physical activity (PA) increases exercise capacity and physical fitness (PF), which can lead to many health benefits. Accurate quantification of PA and PF becomes essential in terms of health outcome and effectiveness of intervention programmes. In this manuscript we present a review regarding the assessment of physical activity and fitness. Three types of PA assessment methods can be distinguished: criterion methods, objective methods and subjective methods. Criterion methods like doubly labelled water, indirect calorimetry and direct observation are the most reliable and valid measurements against which all other PA assessments methods should be validated, but they also hold important drawbacks. Objective PA assessment methods include activity monitors (pedometers and accelerometers) and heart rate monitoring. Finally, questionnaires and activity diaries are considered subjective methods. For the assessment of PF, we distinguish field tests and laboratory tests. The Eurofit for Adults is a test battery that is designed to assess health-related fitness of individuals, communities, sub-populations and populations. It is mainly used for evaluating the morphological component, the muscular component, the motor component and the cardio-respiratory component. In the laboratory, exercise capacity is preferentially assessed through maximal incremental exercise testing. Cardio-pulmonary exercise testing is a well-established procedure that provides a wealth of clinically diagnostic and prognostic information. The peak oxygen uptake is the gold standard in the assessment of exercise tolerance. When maximal exercise is contraindicated or not achievable, the VAT or the submaximal slopes provide reasonable alternatives.

Study Objective: We analyzed the effects of the use of a rollator on walking distance and physiologic variables: pulmonary gas exchange, heart rate, minute ventilation (Ve), oxygen saturation, and symptoms during the 6-min walk test (6MWT) in patients with COPD., Setting: Outpatient clinic at university hospital., Patients: Fourteen patients with COPD in stable clinical condition. One patient had mild COPD, five patients had moderate COPD, six patients had severe COPD, and two patients had very severe COPD., Interventions: Two 6MWTs were performed with a portable metabolic system (VmaxST 1.0; Viasys Healthcare; MEDA; Aartselaar, Belgium) with a rollator and without a rollator, in random order. In addition, maximal voluntary ventilation (MVV) was measured with and without a rollator, randomly., Results: The median 6MWT distance increased significantly with a rollator: 416 m without a rollator (interquartile range [IQR], 396 to 435 m), vs 462 m with a rollator (IQR, 424 to 477 m) [p = 0.04]. Significant increases were also seen in oxygen uptake (0.04 L/min [IQR, - 0.002 to 0.09 L/min]); tidal volume (0.06 L/min [IQR, - 0.001 to 0.11 L/min]); and Ve (0.95 L/min [IQR, - 0.67 to 7.1 L/min]), recorded in the last minute of the 6MWT; as well as in MVV (3 L/min [IQR, 0 to 12 L/min]) [p < 0.05 for all]. Borg dyspnea scores tended to be lower with a rollator: 6 (IQR, 4 to 7) without a rollator, vs 5 (IQR, 4 to 7) with a rollator (p = 0.10). The variation in the 6MWT was explained by individual changes in walking efficiency (partial R(2) = 0.31) and changes in Ve (partial R(2) = 0.36) [p model < 0.04]., Conclusion: The use of a rollator improves walking distance of patients with COPD through an increased ventilatory capacity and/or better walking efficiency.