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Pulmonary rehabilitation programmes including aerobic training improve cardiorespiratory fitness in patients with COPD, but the optimal programme design is unclear. We used random effects additive component network meta-analysis to investigate the relative effectiveness of different programme components on fitness measured by V̇O 2peak in COPD. The included 59 studies involving 2191 participants demonstrated that V̇O 2peak increased after aerobic training of at least moderate intensity with the greatest improvement seen following high intensity training. Lower limb aerobic training (SMD 0.56 95% CI 0.32;0.81, intervention arms=86) and the addition of non-invasive ventilation (SMD 0.55 95% CI 0.04;1.06, intervention arms=4) appeared to offer additional benefit but there was limited evidence for effectiveness of other exercise and non-exercise components., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Despite the wide-ranging benefits of pulmonary rehabilitation, conflicting results remain regarding whether people with COPD can improve their peak oxygen uptake (V˙O 2peak) with aerobic training., Research Question: The goal of this study was to investigate the effect of aerobic training and exercise prescription on V˙O 2peak in COPD., Study Design and Methods: A systematic review was performed by using MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and Cochrane databases for all studies measuring V˙O 2peak prior to and following supervised lower-limb aerobic training in COPD. A random effects meta-analysis limited to randomized controlled trials comparing aerobic training vs usual care was conducted. Other study designs were included in a secondary meta-analysis and meta-regression to investigate the influence of program and patient factors on outcome., Results: A total of 112 studies were included (participants, N = 3,484): 21 controlled trials (n = 489), of which 13 were randomized (n = 288) and 91 were uncontrolled (n = 2,995) studies. Meta-analysis found a moderate positive change in V˙O 2peak (standardized mean difference, 0.52; 95% CI, 0.34-0.69) with the intervention. The change in V˙O 2peak was positively associated with target duration of exercise session (P = .01) and, when studies > 1 year duration were excluded, greater total volume of exercise training (P = .01). Similarly, the change in V˙O 2peak was greater for programs > 12 weeks compared with those 6 to 12 weeks when adjusted for age and sex. However, reported prescribed exercise intensity (P = .77), training modality (P > .35), and mode (P = .29) did not affect V˙O 2peak . Cohorts with more severe airflow obstruction exhibited smaller improvements in V˙O 2peak (P < .001)., Interpretation: Overall, people with COPD achieved moderate improvements in V˙O 2peak through supervised aerobic training. There is sufficient evidence to show that programs with greater total exercise volume, including duration of exercise session and program duration, are more effective. Reduced effects in severe disease suggest alternative aerobic training methods may be needed in this population., Clinical Trial Registration: PROSPERO; No.: CRD42018099300; URL: https://www.crd.york.ac.uk/prospero/., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background: In people with chronic obstructive pulmonary disease (COPD), the use of neuromuscular electrostimulation (NMES) either alone, or together with conventional exercise training, might improve the condition of the peripheral muscles, increase exercise capacity and functional performance, reduce symptoms and improve health-related quality of life (HRQoL)., Objectives: To determine the effects of NMES, applied in isolation or concurrently with conventional exercise training to one or more peripheral muscles, on peripheral muscle force and endurance, muscle size, exercise capacity, functional performance, symptoms, HRQoL and adverse events in people with COPD., Search Methods: We searched the Cochrane Airways Group Specialised Register, the Physiotherapy Evidence Database, clinical trial registries and conference abstracts on 14 March 2018., Selection Criteria: Randomised controlled trials that recruited adults with COPD if they had compared outcomes between a group that received NMES and a group that received usual care or compared outcomes between a group that received NMES plus conventional exercise training and a group that participated in conventional exercise training alone., Data Collection and Analysis: Two review authors independently extracted data and assessed risk of bias using the Cochrane 'Risk of bias' tool. We expressed continuous data as either the standardised mean difference (SMD) or mean difference (MD) with the corresponding 95% confidence interval (CI). We assessed the quality of evidence using the GRADE approach., Main Results: Nineteen studies met the inclusion criteria of which 16 contributed data on 267 participants with COPD (mean age 56 to 76 years and 67% were men). Of these 16 studies, seven explored the effect of NMES versus usual care and nine explored the effect of NMES plus conventional exercise training versus conventional exercise training alone. Six studies utilised sham stimulation in the control group. When applied in isolation, NMES produced an increase in peripheral muscle force (SMD 0.34, 95% CI 0.02 to 0.65; low-quality evidence) and quadriceps endurance (SMD 1.36, 95% CI 0.59 to 2.12; low-quality evidence) but the effect on thigh muscle size was unclear (MD 0.25, 95% CI -0.11 to 0.61; low-quality evidence). There were increases in six-minute walk distance (6MWD) (MD 39.26 m, 95% CI 16.31 to 62.22; low-quality evidence) and time to symptom limitation exercising at a submaximal intensity (MD 3.62 minutes, 95% CI 2.33 to 4.91). There was a reduction in the severity of leg fatigue on completion of an exercise test (MD -1.12 units, 95% CI -1.81 to -0.43). The increase in peak rate of oxygen uptake (VO 2peak ) was of borderline significance (MD 0.10 L/minute, 95% CI 0.00 to 0.19).For NMES with conventional exercise training, there was an uncertain effect on peripheral muscle force (SMD 0.47, 95% CI -0.10 to 1.04; very low-quality evidence) and there were insufficient studies to undertake a meta-analysis on the effect on quadriceps endurance or thigh muscle size. However, there was an increase in 6MWD in favour of NMES combined with conventional exercise training (MD 25.87 m, 95% CI 1.06 to 50.69; very low-quality evidence). In people admitted to either in an intensive care unit or a respiratory high dependency centre, NMES combined with conventional exercise reduced the time taken for participants to first sit out of bed by 4.98 days (95% CI -8.55 to -1.41; very low-quality evidence), although the statistical heterogeneity for this analysis was high (I 2 = 60%). For both types of studies (i.e. NMES versus usual care and NMES with conventional exercise training versus conventional exercise training alone), there was no risk difference for mortality or minor adverse events in participants who received NMES., Authors' Conclusions: NMES, when applied in isolation, increased quadriceps force and endurance, 6MWD and time to symptom limitation exercising at a submaximal intensity, and reduced the severity of leg fatigue on completion of exercise testing. It may increase VO 2peak , but the true effect on this outcome measure could be trivial. However, the quality of evidence was low or very low due to risk of bias within the studies, imprecision of the estimates, small number of studies and inconsistency between the studies. Although there were no additional gains in quadriceps force with NMES plus conventional exercise training, there was evidence of an increase in 6MWD. Further, in people who were the most debilitated, the addition of NMES may have accelerated the achievement of a functional milestone, that is, the first time someone sits out of bed.

Background: In people with COPD, dyspnea is the primary symptom limiting exercise tolerance. One approach to reducing dyspnea during exercise is through music listening. A constant speed endurance test reflects a high-intensity aerobic exercise training session, but whether listening to music affects endurance time is unknown. This study aimed to determine the effects of listening to music during a constant speed endurance test in COPD., Methods: Participants with COPD completed two endurance walk tests, one with and one without listening to self-selected music throughout the test. The primary outcome was the difference in endurance time between the two conditions. Heart rate, percutaneous oxygen saturation, dyspnea, and rate of perceived exertion were measured before and after each test., Results: Nineteen participants (mean [SD]: age, 71 [8] years; FEV 1 , 47 [19] % predicted) completed the study. Endurance time was greater (1.10 [95% CI, 0.41-1.78] min) while listening to music (7.0 [3.1] min) than without (5.9 [2.6] min), and reduced end-test dyspnea (1.0 [95% CI, -2.80 to -1.80] units) (with music, 4.6 [1.7] units; vs without music, 5.6 [1.4] units, respectively). There was not a significant difference in heart rate, percutaneous oxygen saturation, or leg fatigue. There were no adverse events under either condition., Conclusions: In COPD, dyspnea was less while listening to music and was accompanied by an increased tolerance of high-intensity exercise demonstrated by greater endurance time. Practically, the effect was modest but may represent an aid for exercise training of these patients., Trial Registry: Australian New Zealand Clinical Trials Registry; No. ACTRN12617001217392., (Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Rationale: In patients with chronic obstructive pulmonary disease (COPD), partitioned exercise training using one-legged cycling leads to greater improvements in peak oxygen uptake than conventional two-legged cycling., Objectives: We evaluated the feasibility of incorporating one-legged cycling as the principal aerobic training modality for pulmonary rehabilitation in COPD., Methods: Physiotherapists underwent four teaching sessions about the principles and practical implementation of one-legged cycling training. Patients enrolled in a pulmonary rehabilitation program underwent 6-8 weeks of training in which one-legged cycling three times per week was the principal aerobic exercise activity. Participants cycled for 15 minutes with each leg, in each session. An incremental cardiopulmonary exercise test was completed before and after pulmonary rehabilitation along with standard pulmonary rehabilitation outcome measures. Participants and physiotherapists completed a satisfaction survey at the end of the program., Measurements and Main Results: A total of 22 out of 32 participants (14 male; mean [SD] age, 66 [7] years; FEV1% predicted, 32 [17]%; median [interquartile range] Medical Research Council dyspnea scale, 3.5 [3.0-4.3]) completed pulmonary rehabilitation. Peak oxygen uptake increased 1.1 (0.4-1.7) ml·min(-1)·kg(-1) (8%) from baseline (P<0.01). The mean (95% confidence interval) 6-minute-walk test distance improved by 72 (45-98) m (P=0.001). The change in the Chronic Respiratory Questionnaire total score of 1.6 (1.1-2.1; P<0.001) was achieved by improvement in all four domains above the clinically important difference. All the physiotherapists considered one-legged cycling safe and would continue to prescribe it; 75% of participants would recommend it to other patients., Conclusions: One-legged cycling was successfully implemented into a "real-life" pulmonary rehabilitation program, demonstrating improvements in cardiorespiratory fitness with associated improvement in function for patients with moderate/severe COPD. One-legged cycling should be recommended in professional pulmonary rehabilitation guidelines as an option for exercise training and be available in other pulmonary rehabilitation programs. Clinical trial registered with www.clinicaltrials.gov (NCT01930526).

Background: Although the aerobic profile of the quadriceps muscle is reduced in COPD, there is conflicting evidence regarding whether this leads to reduced quadriceps muscle endurance. We, therefore, performed a systematic review of studies comparing quadriceps endurance in individuals with COPD with that in healthy control subjects., Methods: Relevant studies were identified by searching six electronic databases (1946-2011). Full-text articles were obtained after two researchers independently reviewed the abstracts. The results were combined in a random effects meta-analysis, and metaregression models were fitted to assess the influence of the type of measurement., Results: Data were extracted from 21 studies involving 728 individuals with COPD and 440 healthy control subjects. Quadriceps endurance was reduced in those with COPD compared with healthy control subjects (standardized mean difference, 1.16 [95% CI, 1.02-1.30]; P < .001) with a 44.5 s (4.5-84.5 s; P = .029) reduction in COPD (large effect size) when measured using a nonvolitional technique. The relationship between quadriceps endurance in those with COPD and control subjects did not differ when comparing nonvolitional and volitional techniques (P = .22) or when high- or low-intensity tasks (P = .44) were undertaken., Conclusions: Quadriceps endurance is reduced in individuals with COPD compared with healthy control subjects, independent of the type of task performed.

Rationale: Evaluation of the role of walking speeds in chronic obstructive pulmonary disease (COPD) should be preceded by an assessment of its repeatability. This study aimed to establish the repeatability of the usual (susual) and fast (sfast) walking speeds among patients with stable COPD and determine the accuracy of manual measurement., Methods: Participants demonstrated their susual and sfast over 10 m with speed calculated using a stopwatch; the accuracy was confirmed with optical sensors. The walks were repeated after a 5-minute rest; the session was repeated on 2 subsequent days. The coefficient of repeatability (CR) was calculated for both speeds, and their stability over days was determined., Results: A total of 29 participants (forced expiratory volume in 1 second (FEV1) = 43 ± 25% predicted; FEV1/forced vital capacity (FVC) = 41 ± 13%; susual = 60.3 ± 11 m·min; sfast = 74.3 ± 11.5 m·min) completed the study. The CRs for the susual and sfast were 7.5 (95% CI: 5.0-10.0) and 7.1 (95% CI: 4.8-9.4) m·min, respectively. There was a small increase in the susual (5%; P < .001) on the second trial of every day and between successive days (5%; P < .001); the sfast was not different between trials (P = .09) and increased only between day 1 and day 2 (4%; P < .0001). There was no difference between the stopwatch and the sensor determined susual (-0.5 [95% CI: -1.1 to 0.1] m·min; P = .12). The small difference (-2.1 [95% CI: -2.7 to -1.5] m·min; P = .0001) between the methods for sfast was within the CR of the sfast., Conclusions: In patients with moderate to severe COPD, repeated measures of the susual and sfast using a stopwatch support the use of these tests for simple, quick assessments of disability.

Purpose: Partitioning exercise by 1-legged cycling is more effective than conventional training in patients with chronic obstructive pulmonary disease. Similarly, inhaling helium-hyperoxia can extend conventional exercise tolerance. This study aimed to determine whether breathing helium-hyperoxia could increase the tolerance of a high-intensity exercise session achieved by 1-legged cycling., Methods: Participants completed 2 high-intensity, constant power, 1-legged cycle tests to intolerance (tlimit). In a randomized order, they inspired 40% oxygen with the balance helium via mask and 1-way valve, 1-legged helium-hyperoxia (1L-HH), or room air with supplemental oxygen via a nasal cannula, 1-legged nitrogen-hyperoxia (1L-NH). We assessed quadriceps fatigue from the change in maximal voluntary contraction (FMVC) and transcutaneously stimulated twitch force (Ftwitch)., Results: Fifteen participants (forced expiratory volume in 1 second [SD] = 36 [18]% predicted; forced expiratory volume in 1 second/forced vital capacity = 34 [14]%; peak oxygen uptake = 12.8 [2.9] mL · kg · min) completed the study. Self-reported "leg fatigue" was a reason for stopping 25 of 30 tests. There was no significant difference in tlimit (0.2 [-1.4 to 1.8] min) between 1L-HH (12.2 [5.2] min) and 1L-NH (12.0 [4.1] min), or in FMVC measured shortly after HH and NH tests (P= .09). The Ftwitch was less after exercise (P< .05) in both conditions, without a difference between conditions (P= .46)., Conclusions: Inspiring a helium-hyperoxia mixture does not increase the endurance of what would be a typical training session, breathing supplemental oxygen, of high-intensity 1-legged constant power exercise. Leg muscle fatigue was similar after 1-legged exercise with and without breathing the helium mixture.

Background: Hyperinflated patients with COPD breathe against an increased elastic load during physical activity. Arm activities are especially demanding. Some pulmonary rehabilitation programs instruct patients to inhale while raising their arms, whereas others recommend the opposite. This study aimed to determine the effect of coordinating breathing with arm movements on the endurance of a lifting task., Methods: Participants with COPD and hyperinflation completed two (high intensity and severe intensity) rhythmic, constant load-lifting tasks to intolerance (tlimit) before and after attending four "teaching" sessions. Participants were randomly assigned to one of three groups: (1) taught to inhale during the lift, (2) taught to exhale during the lift, or (3) sham (unconstrained coordination)., Results: Thirty-six participants (FEV1 % predicted [SD], 34 [13]; FEV1/FVC [SD], 33% [10%]; thoracic gas volume % predicted [SD], 179 [44]) completed the study. There was an effect of group on the change in tlimit (P<.01) regardless of task intensity (P=.47). The change in tlimit in the exhalation group was greater than in both the sham (difference [95% CI]: 2.82 [0.21-5.44] min; P<.05) and inhalation (difference [95% CI]: 3.29 [0.65-5.92] min; P<.05) groups at the high intensity. There was no difference in the change in tlimit between the inhalation and sham groups., Conclusions: A specific breathing strategy, exhalation during the lift, improved task performance. Coordinating exhalation with lifting may be of value to hyperinflated patients with COPD who are engaged in arm and shoulder training exercises or daily activities that involve arm elevation., Trial Registry: ClinicalTrials.gov; No: NCT00836108; URL: www.clinicaltrials.gov.

Background: The original method for determining endurance shuttle walk test (ESWT) speed involves components that are time consuming for clinicians. We sought to determine: (i) whether components described in the original method for determining ESWT speed held true and; (ii) the agreement between speeds derived using the original method and that equivalent to 85% of the peak speed achieved during the incremental shuttle walk test (ISWT)., Methods: Patients with chronic obstructive pulmonary disease (COPD) performed two ISWTs and one ESWT on separate days, wearing a calibrated portable gas analysis unit. A retrospective analysis of these data allowed us to determine whether: (i) the peak rate of oxygen uptake (V˙O₂peak) can be accurately estimated from the incremental shuttle walk distance (ISWD) and; (ii) ESWTs performed at a speed derived using the original method elicited 85% of V˙O₂peak. Agreement between walks speeds was determined using Bland-Altman analysis., Results: Twenty-two participants (FEV₁ 48 ± 13% predicted, age 66 ± 8 yr) completed the study. The V˙O₂peak estimated from the ISWD was less than that measured during the ISWT (mean difference -4.4; 95% confidence interval (CI), -6.0 to -2.9 ml· kg⁻¹·min⁻¹). The ESWT and ISWT elicited similar V˙O₂peak (mean difference -0.2; 95% CI, -1.5 to 1.2 ml·kg⁻¹·min⁻¹). The mean difference (±limits of agreement) between ESWT speeds was 0.15 (±0.34) km·h⁻¹., Conclusions: Components of the original method for determining the ESWT speed did not hold true in our sample. ESWT speed can be derived by calculating 85% of the peak speed achieved during the ISWT., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Objectives: To (1) evaluate whether the use of a rollator changed metabolic cost during a controlled walking task, and (2) explore relationships between the difference in dyspnea and metabolic cost associated with rollator use., Design: Single-group interventional study in which patients completed 2 corridor walks: 1 without and 1 with a rollator, at the same individualized constant speed., Setting: Rehabilitation hospital., Participants: Patients with chronic obstructive pulmonary disease (N=15; 10 men; median age [interquartile range; IQR]=69 [12]y; forced expiratory volume in 1 second=42 [20]% predicted)., Intervention: Rollator use., Main Outcome Measures: Oxygen uptake, converted to metabolic equivalent units (METs), and minute ventilation were measured throughout both tasks using a portable gas analysis system; dyspnea and arterial oxygen saturation (SpO(2)) were collected on completion., Results: Median [IQR] walk speed [IQR] was 48 (10)m/min. Walking with a rollator, compared with walking without, reduced dyspnea (median [IQR]=1.0 [1.5] vs 2.0 [2.0]; P=.01) without changing energy expenditure (median [IQR]=2.8 [1.2] vs 3.2 [0.9] METs; P=.65), minute ventilation (median [IQR]=30.3 [9.6] vs 27.7 [9.9]L/min; P=.50), or SpO(2) (median [IQR]=92 [8]% vs 94 [10]%; P=.41). The association between the reduction in dyspnea and any difference in energy expenditure related to rollator use was of borderline significance (r(s)=.50; P=.06). Six of the 8 participants who experienced a reduction in dyspnea also demonstrated a reduction in the metabolic cost of walking., Conclusions: The mechanism responsible for the amelioration in dyspnea during rollator-assisted walking is multifactorial. A reduction in the metabolic cost of walking may play a part in some, but not all, patients., (Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Along with age and sex, socioeconomic status is one of the most powerful determinants of health. We conducted a systematic review to examine the consistency and magnitude of the association between socioeconomic status and COPD health outcomes to determine the potential impact of SES disparity on the COPD population., Methods: Electronic databases to October 2011 were searched for studies of adults who had or were at risk for COPD that quantified an association between a measure of socioeconomic status and at least one COPD health outcome. Two authors independently reviewed studies, assessed study quality, and for eligible studies, extracted data., Results: Regardless of the population, socioeconomic status measure or COPD outcome examined, with few exceptions, consistent significant inverse associations between socioeconomic status and COPD outcomes were found. Most studies found that individuals of the lowest socioeconomic strata were at least twice as likely to have poor outcomes as those of the highest (range from no difference to 10-fold difference)., Conclusions: Social and economic disadvantage appears to have a significant consistent impact on COPD mortality and morbidity. These findings point to the need for public health strategies and research to address socioeconomic status disparity in individuals with COPD.

Background: Walking is frequently used in the exercise rehabilitation of patients with COPD. Walking ability can be characterized by the two-parameter hyperbolic relationship between endurance and speed. One parameter, critical walk speed (s&#95;critical), represents the maximum speed that can be endured indefinitely. The purpose of this study was to: (1) determine the effect of pulmonary rehabilitation on the critical speed and (2) compare the critical speed with the speed chosen during self-paced walking., Methods: We estimated critical speed in patients with COPD before and after rehabilitation. Patients completed four high-intensity constant-speed walk tests to intolerance on a 30-m course. The parameters of the hyperbolic relationship were determined using nonlinear regression of endurance on speed. Participants also completed self-paced walks: (1) for as long as they could, (2) at their "usual" and "fast" speeds, and (3) as a 6-min walk test., Results: Twelve participants (FEV(1) [SD], 41 [16] % predicted; FEV(1)/FVC, 41 [12]) completed the study. At baseline, the critical speed (65 [12] m/min) was not significantly different from the self-paced, usual, or 6-min walk speeds (65 [12], 67 [14], and 63 [15] m/min, respectively). There was a significant increase in critical speed (6 [1-10] m/min) and 6-min speed (16 [10-21] m/min) after rehabilitation, without changes in the self-paced, usual, or fast speeds., Conclusions: Patients with COPD increase their critical walk speed after pulmonary rehabilitation. The pace chosen during common walk tasks is closely related to critical speed; this relationship is altered after rehabilitation., Trial Registry: ClinicalTrials.gov; No.: NCT00781183; URL: www.clinicaltrials.gov.

Background: The aims of this study were to determine which tests of exercise capacity relate to average daily energy expenditure (DEE) and to quantify aerobic reserve during daily life in people with COPD., Methods: A cross-sectional study was undertaken in 26 people with COPD (16 men; FEV(1), 50% ± 16%). Six-min walk distance (6MWD) and incremental shuttle walk distance (ISWD) measures were collected, and peak oxygen uptake (VO(2) peak) was measured during a symptom-limited ramp cycle ergometry test. The SenseWear Armband was worn during the waking hours for 4.4 ± 1.1 days to measure DEE. The intensity at which activities of daily living were undertaken was expressed as a percentage of VO(2) peak., Results: DEE was associated with 6MWD (r = 0.40, P = .046) and ISWD (r = 0.52, P = .007) but not VO(2) peak (mL/kg per min) (r = 0.07, P = .74). Stronger associations were observed between DEE and the body weight-walking distance product for the 6MWD (r = 0.73, P < .001) and ISWD (r = 0.75, P < .001). The average intensity of daily activity was equivalent to 58% ± 11% of VO(2) peak, leaving an average aerobic reserve of 42%., Conclusions: Both 6MWD and ISWD, but not VO(2) peak, were related to DEE. Because activities of daily living were performed at a high percentage of VO(2) peak, it may be more realistic to optimize habitual DEE in COPD by increasing the frequency or duration rather than the intensity of physical activity.

Background and Objective: Field and laboratory-based tests are used to measure exercise capacity in people with COPD. A comparison of the cardiorespiratory responses to field tests, referenced to a laboratory test, is needed to appreciate the relative physiological demands. We sought to compare peak and submaximal cardiorespiratory responses to the 6-min walk test, incremental shuttle walk test and endurance shuttle walk test with a ramp cycle ergometer test (CET) in patients with COPD., Methods: Twenty-four participants (FEV(1) 50 ± 14%; 66.5 ± 7.7 years; 15 men) completed four sessions, separated by ≥24 h. During an individual session, participants completed either two 6-min walk tests, incremental shuttle walk tests, endurance shuttle walk tests using standardized protocols, or a single CET, wearing a portable gas analysis unit (Cosmed K4b(2)) which included measures of heart rate and arterial oxygen saturation (SpO(2))., Results: Between tests, no difference was observed in the peak rate of oxygen uptake (F(3,69) = 1.2; P = 0.31), end-test heart rate (F(2,50) = 0.6; P = 0.58) or tidal volume (F(3,69) = 1.5; P = 0.21). Compared with all walking tests, the CET elicited a higher peak rate of carbon dioxide output (1173 ± 350 mL/min; F(3,62) = 4.8; P = 0.006), minute ventilation (48 ± 17 L/min; F(3,69) = 10.2; P < 0.001) and a higher end-test SpO(2) (95 ± 4%; F(3,63) = 24.9; P < 0.001)., Conclusions: In patients with moderate COPD, field walking tests elicited a similar peak rate of oxygen uptake and heart rate as a CET, demonstrating that both self- and externally paced walking tests progress to high intensities., (© 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology.)

Background: Patients with chronic respiratory diseases often have the simple goal of wanting to walk for longer. We evaluated the properties of a patient goal-oriented, symptom-limited, self-paced walk (SPW)., Methods: Patients with symptomatic chronic respiratory disease, referred for a 6-week course of pulmonary rehabilitation (PR), were screened for eligibility. Baseline assessments included two SPWs with both time and speed measured, two 6-min walk tests (6MWTs), and the Medical Research Council dyspnea scale. On program completion, two SPWs and one 6MWT were performed. The repeatability, responsiveness, and validity of the SPW were assessed., Results: Two SPWs were completed by 50 and 37 patients before and after rehabilitation, respectively. The speed (r = -0.54, P < .001) but not the time (r = -0.23, P = .19) of the SPW correlated with Medical Research Council dyspnea grade. The mean SPW time increased on the second day of testing from 15.1 ± 8.4 min to 17.9 ± 7.7 min (P = .004), and the effect of test day was unaltered by PR (P = .80). The coefficient of repeatability for SPW time was 16.1 min. Both the mean SPW time (10.6 min; 95% CI, 6.6-14.5 min; P < .001) and the mean speed (3.5 m/min; 95% CI, 1.3-5.7 m/min; P < .01) increased after rehabilitation., Conclusions: The SPW time is an easily understandable, patient goal-oriented assessment with construct validity that is highly responsive to the effects of PR. The variability in SPW time makes it better suited to interpreting group rather than individual changes., Trial Registry: ClinicalTrials.gov; No.: NCT00781183; URL: www.clinicaltrials.gov.

Background: The study aimed to evaluate the effect of upper extremity resistance training for patients with COPD on dyspnea during activity of daily living (ADL), arm function, arm exercise capacity, muscle strength, and health-related quality of life (HRQL)., Methods: Patients were randomly assigned to an intervention or control group. The intervention group underwent arm resistance training. The control group performed a sham. Both groups exercised three times a week for 6 weeks. Dyspnea during ADL and HRQL were measured using the Chronic Respiratory Disease Questionnaire (CRDQ). Arm function and exercise capacity were measured using the 6-min pegboard and ring test (6PBRT) and the unsupported upper limb exercise test (UULEX), respectively. Muscle strength for the biceps, triceps, and anterior and middle deltoids was obtained using an isometric dynamometer., Results: Thirty-six patients with COPD (66 ± 9 years) participated in the study. Compared with the control group, the magnitude of change in the intervention group was greater for the 6PBRT (P = .03), UULEX (P = .01), elbow flexion force (P = .01), elbow extension force (P = .02), shoulder flexion force (P = .029), and shoulder abduction force (P = .01). There was no between-group difference in dyspnea during ADL, HRQL, or symptoms during the 6PBRT or UULEX (all P values > .08)., Conclusions: Resistance-based arm training improved arm function, arm exercise capacity, and muscle strength in patients with COPD. No improvement in dyspnea during ADL, HRQL, or symptoms was demonstrated.

Purpose: Reduced maximal, peripheral muscle strength is associated with exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). Therefore, it is important to accurately evaluate muscle strength to identify patients with muscle weakness and to prescribe adequate loads for resistance training. The objective here was to systematically identify and summarize the literature on measurement of peripheral muscle strength in individuals with COPD and to make recommendations for strength testing in clinical and research settings., Methods: A literature search was conducted of electronic databases between 1999 and 2009 of all English language articles utilizing muscle strength measurements., Results: The search resulted in retrieval of 178 articles, of which 66 were reviewed. Isometric muscle strength was measured using handgrip (n = 30), strain gauge (n = 15), computerized dynamometer (n = 13), magnetic stimulation (n = 8), handheld dynamometer (n = 6), or manual testing (n = 3). Isotonic muscle strength was measured using a hydraulic system (n = 3) or 1-repetition maximum (n = 9), and isokinetic muscle strength was measured using computerized dynamometer (n = 16). Methodological issues such as limb position, number of trials, subject familiarization, test instructions, rest periods, and muscle group tested were all identified as important variables to consider when developing a strength-testing protocol., Conclusion: Muscle strength has been measured in people with COPD using similar methods as in other clinical populations. Each method presents advantages and disadvantages that need to be considered when selecting the most relevant measure. Standardization of the test procedures is essential in both clinical and research settings to obtain valid and reliable measurements of muscle strength.

Rationale: The SenseWear armband (SAB) is designed to measure energy expenditure (EE). In people with chronic obstructive pulmonary disease (COPD), EE estimated using the SAB (EE(SAB)) is a popular outcome measure. However, a detailed analysis of the measurement properties of the SAB in COPD is lacking., Objective: To examine the sensitivity of EE(SAB), agreement between EE(SAB) and EE measured via indirect calorimetry (EE(IC)), and its repeatability in COPD., Methods: 26 people with COPD (forced expiratory volume in 1 s (FEV(1))=49+/-18% predicted; 15 males) spent 6 min in five standardised tasks that comprised supine, sitting, standing and two walking speeds. A subgroup (n=12) walked using a rollator. Throughout each task, measurements of EE(SAB) and EE(IC) were collected. The protocol was repeated on a second day., Results: EE(SAB) increased between standing and slow walking (2.4, metabolic equivalents (METs) 95% CI 2.2 to 2.7) as well as slow and fast walking (0.5 METs, 95% CI 0.3 to 0.7). Considering all tasks together, the difference between EE(SAB) and EE(IC) was -0.2 METs (p=0.21) with a limit of agreement of 1.3 METs. The difference between days in EE(SAB) was 0.0 METs with a coefficient of repeatability of 0.4 METs. Rollator use increased the variability in EE(SAB), compromising its repeatability and agreement with EE(IC)., Conclusions: EE(SAB) was sensitive to small but important changes. There was fair agreement between EE(SAB) and EE(IC), and measurements of EE(SAB) were repeatable. These observations suggest that the SAB is useful for the evaluation of EE in patients with COPD who walk without a rollator.

Background: In patients with chronic obstructive pulmonary disease (COPD), interval exercise has gained recent attention as a possible means of achieving greater physiological training effects compared with continuous exercise. The primary aim of this systematic review was to compare the effects of interval versus continuous training on peak oxygen uptake, peak power, 6 minute walk test (6MWT) distance and health-related quality of life in individuals with COPD., Methods: Randomised controlled trials comparing the effects of interval versus continuous training in patients with COPD were identified after searches of six databases and reference lists of appropriate studies in May 2009. Two reviewers independently assessed study quality. Weighted mean differences (WMD) with 95% CIs were calculated using a random effects model for measures of exercise capacity and health-related quality of life., Results: Eight randomised controlled trials, with a total of 388 patients with COPD, met the inclusion criteria. No significant differences were found for peak power (WMD 1 W, 95% CI -1 to 3) or peak oxygen uptake (WMD -0.04 l/min, 95% CI -0.13 to 0.05) between interval and continuous training. The WMD for the Chronic Respiratory Questionnaire dyspnoea score was -0.2 units (95% CI -0.5 to 0.0). There was no difference in 6MWT distance between groups (WMD 4 m, 95% CI -15 to 23)., Conclusions: Interval and continuous training modalities did not differ in their effect on measures of exercise capacity or health-related quality of life. Interval training may be considered as an alternative to continuous training in patients with varying degrees of COPD severity.

Background: The protocol used for the 6-min walk test (6MWT) influences its results. The only study to examine the effect of modifying track layout performed a retrospective analysis and concluded that institutions using continuous tracks yield greater distances than those using straight tracks. Agreement between the distances measured on different tracks could not be examined. We evaluated the effect of modifying track layout on walk distance and examined the agreement and repeatability of distances measured on different tracks., Methods: In a prospective, randomized, cross-over study, 27 COPD subjects (FEV(1), 38 +/- 14% [mean +/- SD]; 15 men) attended three separate test sessions, completing six 6MWTs. To familiarize all subjects with both tracks, the first two sessions comprised two 6MWTs on either a circular or straight track. During the final session, each subject was tested once on the straight and once on the circular track., Results: The distance walked on the circular track exceeded the straight track by 13 +/- 17 m (p < 0.001). The limit of agreement between tracks was 33 m. Coefficient of repeatability values when the test was completed on different days for the straight and circular tracks were 51 m and 65 m, respectively., Conclusions: When evaluating changes in 6-min walk distance in groups of patients, track layout should be standardized. However, the effect of modifying track layout on an individual's walking distance is small compared to their daily variability in walk distance. Therefore, standardizing track layout for any given individual may be inconsequential when evaluating the change in distances from tests performed on different days.

Background: Most patients with severe COPD are limited by dyspnea and are obliged to exercise at low intensity. Even those undergoing training do not usually have increased peak oxygen uptake (Vo2). One-legged exercise, at half the load of two-legged exercise, places the same metabolic demands on the targeted muscles but reduces the ventilatory load, enabling patients to increase work capacity. The purpose of this study was to determine whether one-legged exercise training would improve aerobic capacity compared with two-legged training in stable patients with COPD., Methods: Eighteen patients with COPD (mean FEV(1), 38 +/- 17% of predicted [+/- SD]) were randomized to two groups after completing an incremental exercise test. Both trained on a stationary cycle for 30 min, 3 d/wk, for 7 weeks. Two-legged trainers (n = 9) cycled continuously for 30 min, whereas one-legged trainers (n = 9) switched legs after 15 min. Intensity was set at the highest tolerated and increased with training., Results: Both groups increased their training intensity (p < 0.001) and total work (p < 0.001). After training, the change in peak Vo2 of the one-legged group (0.189 L/min; confidence interval [CI], 0.089 to 0.290 L/min; p < 0.001) was greater than that of the two-legged group (0.006 L/min; CI, - 0.095 to 0.106 L/min; p = 0.91). This was accompanied by greater peak ventilation (4.4 L/min; CI, 1.8 to 7.1 L/min; p < 0.01) and lower submaximal heart rate (p < 0.05) and ventilation (p < 0.05) in the one-legged trained group., Conclusion: Reducing the total metabolic demand by using one-legged training improved aerobic capacity compared with conventional two-legged training in patients with stable COPD.

Background: In patients with COPD, exercise intensity is often limited by the ventilatory system. We hypothesized that by exercising with a smaller muscle mass, ventilatory-limited patients would perform more high-intensity, muscle-specific work. The study objectives were as follows: (1) to determine the limitations of exercising with a smaller muscle mass, compared with conventional two-legged exercise; and (2) to determine the endurance time, using the same muscle-specific intensity, during one-legged vs two-legged exercise., Methods: Nine patients (mean +/- SD FEV1, 36 +/- 13% of predicted) completed incremental exercise, and nine other patients (mean FEV1, 42 +/- 16% of predicted) completed constant-power exercise. Nine healthy subjects (FEV1, 104 +/- 14% of predicted) completed both tests. All subjects completed tests using two-legged and one-legged pedaling., Results: Peak oxygen uptake (VO2peak) was similar during one-legged and two-legged incremental exercise among patients (difference, 0.03 L/min; 95% confidence interval [CI], -0.10 to 0.16 L/min; p = 0.60), as were ventilation and dyspnea scores. VO2peak was lower during one-legged vs two-legged exercise (-0.57 mL/min; 95% CI, -0.81 to -0.32 mL/min; p < 0.001) among healthy subjects with substantial ventilatory and heart rate reserve. Patients endured one-legged pedaling at a constant power longer than two-legged pedaling (16.97 min; 95% CI, 9.98 to 23.96 min; p < 0.001), resulting in greater work (12.48 kilojoules [kJ]; 95% CI, 2.58 to 22.39 kJ; p = 0.02). Healthy subjects completed similar work (-4.02 kJ; 95% CI, -18.59 to 10.55 kJ; p = 0.54) with one-legged vs two-legged pedaling., Conclusion: These observations demonstrate the effectiveness of using one-legged exercise at the same muscle-specific intensity in extending the duration of exercise among patients with COPD. This has important implications for training approaches designed to enhance exercise function among ventilatory-limited patients.

Study Objective: Estimating lung volume using inspiratory capacity (IC) maneuvers is a useful way of tracking dynamic hyperinflation. An understanding of the repeatability of the IC in a clinical setting is important when evaluating an individual's response to a therapeutic intervention that might influence lung volume. This is the first study to determine the repeatability of serial IC measurements of patients with severe COPD undergoing incremental exercise testing in a clinical setting., Subjects and Methods: Ten patients with severe COPD, inexperienced in exercise testing, cycled with power increased until they reached symptom limitation. Flow was measured at the mouth using a pneumotachograph. IC maneuvers were performed at 1-min to 3-min intervals. Subjects repeated the exercise test 2 days later. Three methods of calculating IC from flow have been described previously. To determine which method provided the best repeatability, we calculated the following: (1) IC calculated by the integration of inspired flow from the start to the end of the IC maneuver (ICINSP); (2) IC calculated from the difference between the drift-corrected peak inspiratory volume (total lung capacity [TLC]) and the drift-corrected end-expiratory lung volume (EELV) of the six breaths that preceded the IC prompt (ICREG); and (3) IC calculated, after correction of the expiratory part of the signal, as the difference between the mean EELV of the six breaths that preceded the IC prompt and the peak inspiratory volume (ICRATIO). Each individual's IC response was expressed as a function of exercise time and of ventilation., Results: There was a significant (p < 0.05) decrease in the expired volume of the breath before the IC maneuver (0.11 +/- 0.26 L) [mean +/- SD]. ICINSP (1.78 +/- 0.88 L) was significantly less than the IC calculated using the other two methods (ICREG, 1.88 +/- 0.89 L; ICRATIO, 1.86 +/- 0.87 L). ICRATIO improved the repeatability of the serial IC measures by as much as 60% over ICINSP and ICREG., Conclusion: Calculating IC as the difference between EELV and TLC was unaffected by unsatisfactory technique, such as a change in breathing pattern immediately before the maneuver. Adjusting expiratory flow based on premaneuver inspiratory to expiratory volume ratio before estimating EELV improved the repeatability coefficient of the IC.