***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: RATIONALE Exercise-induced dynamic hyperinflation contributes to decreased exercise tolerance in chronic obstructive pulmonary disease ( COPD ) . It is unknown whether respiratory retraining ( ventilation-feedback [ VF ] training ) can affect exercise-induced dynamic hyperinflation and increase exercise tolerance . OBJECTIVES To determine whether patients with COPD would achieve longer exercise duration if r and omized to a combination of exercise training plus VF training than either form of training on its own . METHODS A total of 64 patients r and omized to 1 of 3 groups : VF plus exercise ( n = 22 ) , exercise alone ( n = 20 ) , and VF alone ( n = 22 ) . MEASUREMENTS AND MAIN RESULTS Exercise duration before and after 36 training sessions and exercise-induced dynamic hyperinflation and respiratory pattern before and after training were measured . In the 49 patients who completed training , duration of constant work-rate exercise was 40.0 ( + /- 20.4 ) minutes ( mean + /- SD ) with VF plus exercise , 31.5 ( + /- 17.3 ) minutes with exercise alone , and 16.1 ( + /- 19.3 ) minutes with VF alone . Exercise duration was longer in VF plus exercise than in VF alone ( P < 0.0001 ) , but did not reach predetermined statistical significance when VF plus exercise was compared with exercise alone ( P = 0.022 ) ( because of multiple comparisons , P < /= 0.0167 was used for statistical significance ) . After training , exercise-induced dynamic hyperinflation , measured at isotime , in VF plus exercise was less than in exercise alone ( P = 0.014 for between-group changes ) and less than in VF alone ( P = 0.019 for between-group changes ) . After training , expiratory time was longer in VF plus exercise training ( P < 0.001 ) , and it was not significantly changed in the other two groups . CONCLUSIONS The combination of VF plus exercise training decreases exercise-induced dynamic hyperinflation and increases exercise duration more than VF alone . An additive effect to exercise training from VF was not demonstrated by predetermined statistical criteria The purpose of this study was to assess the effects of a particular breathing pattern training ( BPT ) on forced expiratory volume during the first second ( FEV1 ) and forced vital capacity ( FVC ) in patients with chronic obstructive pulmonary disease ( COPD ) . The subjects adjusted each breath to a target breath displayed on a video screen , by using visual feedback . This target was chosen in an individual sample recorded at rest . We used a r and omized , controlled group design . Twenty patients with stable COPD , FEV1 less than 1.5 liters , undergoing a traditional rehabilitation program were r and omly assigned to the  BPT  group or to the control group . Each BPT  subject underwent 30–35 training sessions spread out over four weeks , in addition to the traditional program . FEV1 and FVC were performed before and after this program . ANOVAs showed that FEV1 and FVC significantly improved in BPT subjects , with a mean percent increase of 22 % and 19 % , respectively . Corresponding changes in controls were not significant . This study showed short-term increases in FEV1 and FVC in COPD patients practicing BPT  in addition to respiratory rehabilitation , in comparison with controls . Further studies should incorporate outcome data to clarify the mechanisms and the duration of this effect BACKGROUND There has been limited study of yoga training as a complementary exercise strategy to manage the symptom of dyspnea in patients with chronic obstructive pulmonary disease ( COPD ) . PURPOSE The primary purpose of this pilot study was to evaluate a yoga program for its safety , feasibility , and efficacy for decreasing dyspnea intensity ( DI ) and dyspnea-related distress ( DD ) in older adults with COPD . METHODS Clinical ly stable patients with COPD ( n = 29 ; age 69.9 + /- 9.5 ; forced expiratory volume in 1 second ( FEV(1 ) ) 47.7 + /- 15.6 % predicted ; female = 21 ) were r and omized to a 12-week yoga program specifically design ed for people with COPD or usual-care control  ( UC ) . The twice-weekly yoga program included asanas ( yoga postures ) and visama vritti pranayama ( timed breathing ) . Safety measure outcomes included heart rate , oxygen saturation , dyspnea , and pain . Feasibility was measured by patient-reported enjoyment , difficulty , and adherence to yoga sessions . At baseline and at 12 weeks , DI and DD were measured during incremental cycle ergometry and a 6-minute walk ( 6MW ) test . Secondary efficacy outcomes included physical performance , psychologic well-being , and health-related quality of life ( HRQoL ) . RESULTS Yoga training was safe and feasible for patients with COPD . While yoga training had only small effects on DI after the 6MW test ( effect size [ ES ] , 0.20 ; p = 0.60 ) , there were greater reductions in DD in the yoga group compared to UC ( ES , 0.67 ; p = 0.08 ) . Yoga training also improved 6MW distance ( + 71.7 + /- 21.8 feet versus -27.6 + /- 36.2 feet ; ES = 0.78 , p = 0.04 ) and self-reported functional performance ( ES = 0.79 , p = 0.04 ) compared to UC . There were small positive changes in muscle strength and HRQoL. CONCLUSIONS Elderly patients with COPD participated safely in a 12-week yoga program especially design ed for patients with this chronic illness . After the program , the subjects tolerated more activity with less DD and improved their functional performance . These findings need to be confirmed in a larger , more sufficiently powered efficacy study Background : Conventional pulmonary rehabilitation programs improve exercise tolerance but have no effect on pulmonary function in patients with chronic obstructive pulmonary disease ( COPD ) . The role of controlled breathing using respiratory biofeedback during rehabilitation of patients with COPD remains unclear . Objectives : To compare the effects of a conventional 4-week pulmonary rehabilitation program with those of rehabilitation plus controlled breathing interventions . Methods : A r and omized controlled trial was performed . Pulmonary function ( FEV1 ) , exercise capacity ( 6-min walking distance , 6MWD ) , health-related quality of life ( chronic respiratory question naire , CRQ ) and cardiac autonomic function ( rMSSD ) were evaluated . Results : Forty COPD patients ( mean ± SD age 66.1 ± 6.4 , FEV1 45.9 ± 17.4 % predicted ) were r and omized to rehabilitation ( n = 20 ) or rehabilitation plus controlled breathing ( n = 20 ) . There were no statistically significant differences between the two groups regarding the change in FEV1 ( mean difference –0.8 % predicted , 95 % CI –4.4 to 2.9 % predicted , p = 0.33 ) , 6MWD ( mean difference 12.2 m , 95 % CI –37.4 to 12.2 m , p = 0.16 ) , CRQ ( mean difference in total score 0.2 , 95 % CI –0.1 to 0.4 , p = 0.11 ) and rMSSD ( mean difference 2.2 ms , 95 % CI –20.8 to 25.1 ms , p = 0.51 ) . Conclusions : In patients with COPD undergoing a pulmonary rehabilitation program  , controlled breathing using respiratory biofeedback has no effect on exercise capacity , pulmonary function , quality of life or cardiac autonomic function OBJECTIVES Patients with chronic obstructive lung disease ( COPD ) suffer from significant dyspnea and may benefit from complementary and alternative medicine ( CAM ) therapies aim ed at mitigating symptoms . The objective of this study was to test the efficacy of a mindfulness-based breathing therapy ( MBBT ) on improving symptoms and health-related quality of life in those with COPD . DESIGN We conducted a r and omized controlled trial of 8-week mindfulness-based breathing therapy ( MBBT ) compared to support groups to test efficacy on improving symptoms and health-related quality of life in those with COPD . SETTING The setting for this study was an academic-affiliated veterans healthcare system . SUBJECTS The subjects consisted of 86 patients with COPD . INTERVENTIONS MBBT included weekly meetings practicing mindfulness mediation and relaxation response . OUTCOME MEASURES The main outcome measure was a post 6-minute-walk test ( 6MWT ) Borg dyspnea assessment . Other outcome measures included health-related quality of life measures , 6MWT distance , symptom scores , exacerbation rates , and measures of stress and mindfulness . Analysis of covariance compared differences in outcomes between groups ; paired t test evaluated changes within groups . RESULTS Participants were predominantly elderly men with moderate to severe COPD . We found no improvements in dyspnea ( post 6MWT Borg difference between the MBBT and support group was 0.3 ( 95 % confidence interval [ CI ] : -1.1 , 1.7 ) . We found no differences between groups in almost all other outcome measures by either intention-to-treat analysis or within the subset that completed assigned group sessions . For the physical summary scale of the generic Short Form-36 for Veterans , the difference between outcomes favored the support group ( 4.3 , 95 % CI : 0.4 , 8.1 ) . Participant retention was low compared to mind-body trials that r and omize from CAM wait lists . CONCLUSIONS This trial found no measurable improvements in patients with COPD receiving a mindfulness-based breathing CAM therapy compared to a support group , suggesting that this intervention is unlikely to be an important therapeutic option for those with moderate-to-severe COPD QUESTION Does a new positive expiratory pressure device ( conical-PEP ) decrease lung hyperinflation during exercise in patients with chronic obstructive pulmonary disease compared to normal breathing ? Does it increase the duration of exercise ? DESIGN A r and omised , cross-over trial with concealed allocation . PARTICIPANTS Thirteen patients with moderate to severe chronic obstructive pulmonary disease ( mean FEV1 61 % predicted ) . INTERVENTION THE experimental intervention was conical-PEP breathing with a positive expiratory pressure of 4 - 20 cmH2O during 30 % of 1 RM alternate knee extension exercise at 70 % age-predicted HRmax to fatigue . The control intervention was normal breathing . OUTCOME MEASURES Total lung capacity ( inspiratory capacity and slow vital capacity ) , breathlessness , and leg discomfort were measured pre and post exercise . Cardiorespiratory function was measured pre and during the last 30 s of exercise . Duration of exercise was recorded . RESULTS After the experimental intervention , inspiratory capacity increased 200 ml ( 95 % CI 0 to 400 ) and slow vital capacity increased 200 ml ( 95 % CI 0 to 400 ) more than the control intervention . Participants exercised for 107 s ( 95 % CI -23 to 238 ) more during the experimental intervention than the control intervention . Conical-PEP breathing during exercise result ed in 6.1 fewer breaths/min ( 95 % CI 1.4 to 10.8 ) than normal breathing ; it did not have any adverse effects on CO2 retention or oxygen saturation . CONCLUSION The novel conical-PEP device decreases lung hyperinflation , is safe to use , and tends to increase the duration of exercise . TRIAL REGISTRATION NCT00741832 Background : Chronic obstructive pulmonary disease ( COPD ) is a leading cause of death and 70 % of the cost of COPD is due to hospitalizations . Self-reported daily physical activity  and health status have been reported as predictors of a hospitalization in COPD but are not routinely assessed . Objectives : We tested the hypothesis that  self-reported daily physical activity and health status assessed by a simple question were predictors of a hospitalization in a well-characterized cohort of patients with severe emphysema . Methods : Investigators gathered daily physical activity and health status data assessed by a simple question  in 597 patients with severe emphysema and tested the association of those patient-reported outcomes to the occurrence of a hospitalization in the following year . Multiple logistic regression analyses were used to determine predictors of hospitalization during the first 12 months after r and omization . Results : The two variables tested in the hypothesis were significant predictors of a hospitalization after adjusting for all univariable significant predictors : > 2 h of physical activity per week had a protective effect [ odds ratio ( OR ) 0.60 ; 95 % confidence interval ( 95 % CI ) 0.41–0.88 ] and self-reported health status as fair or poor had a deleterious effect ( OR 1.57 ; 95 % CI 1.10–2.23 ) . In addition , two other variables became significant in the multivariate model : total lung capacity ( every 10 % increase ) had a protective effect ( OR 0.88 ; 95 % CI 0.78–0.99 ) and self-reported anxiety had a deleterious effect ( OR 1.75 ; 95 % CI 1.13–2.70 ) . Conclusion : Self-reported daily physical activity and health status are independently associated with COPD hospitalizations . Our findings , assessed by simple questions , suggest the value of patient-reported outcomes in developing risk assessment tools that are easy to use OBJECTIVES To compare the effect of respiratory muscle stretch gymnastics ( RMSG ) , proposed 
    Output:
    
Effects on dyspnoea and health-related quality of life were inconsistent across trials .
Breathing exercises over four to 15 weeks improve functional exercise capacity in people with COPD compared to no intervention ; however , there are no consistent effects on dyspnoea or health-related quality of life .
Outcomes were similar across all the breathing exercises examined .
Breathing exercises may be useful to improve exercise tolerance in selected individuals with COPD who are unable to undertake exercise training ; however , these data do not suggest a widespread role for breathing exercises in the comprehensive management of people with COPD