A simple method to derive speed for the endurance shuttle walk test

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 (VO2peak) 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 VO2peak. 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 VO2peak 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 VO2peak (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

Arm Elevation and Coordinated Breathing Strategies in Patients with COPD

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

Is quadriceps endurance reduced in COPD?: A systematic review

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

Change in V˙O_2peak in response to aerobic exercise training and the relationship with exercise prescription in people with COPD: a systematic review and meta-analysis

BACKGROUND: ▪▪▪ RESEARCH QUESTION: The goal of this study was to investigate the effect of aerobic training and exercise prescription on peak oxygen uptake (V˙O2peak) 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˙O2peak 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˙O2peak (standardized mean difference, 0.52; 95% CI, 0.34-0.69) with the intervention. The change in V˙O2peak 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˙O2peak 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˙O2peak. Cohorts with more severe airflow obstruction exhibited smaller improvements in V˙O2peak (P < .001). INTERPRETATION: Overall, people with COPD achieved moderate improvements in V˙O2peak 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: www.clinicaltrials.gov

Understanding the effectiveness of different exercise training programme designs on V̇O_2peakin COPD: a component network meta-analysis

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 V̇O2peakin COPD. The included 59 studies involving 2191 participants demonstrated that V̇O2peakincreased 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