Outcomes of progressive resistance exercise for people with COPD

CONCLUSIONS:When performed consistently, predominantly home-based PRE canimprove muscle strength, dyspnoea, fatigue, and perceptions ofcontrol during activity for people with COPD. The physical outcomesof short-term PRE decline after training stops, but psychologicalbenefits influencing activity may persist. IMPLICATIONS: Longerduration exercise interventions may be necessary to maximiserehabilitation outcomes for people with COPD. Further research isrequired to determine optimal maintenance dose exercise prescriptions,effective and cost-efficient methods for delivering maintenanceprograms, and factors influencing long-term exercise adherence inthis population. KEYWORDS: COPD, pulmonary rehabilitation, progressiveresistance exercise. FUNDING ACKNOWLEDGEMENTS:1. Equipment Grant ' Theraband Academy, Hygenic Corporation,USA. 2. Postgraduate Support Grants ' School of Physiotherapyand Faculty of Health Sciences, La Trobe University. CONTACT:[email protected] ETHICS COMMITTEE: La Trobe University; The Alfred Hospital;Wodonga Regional Health Service; Northeast Health Wangaratta;Wagga Wagga Base HospitalPURPOSE: To examine the effectiveness and efficacy of apredominantly home-based 12 week progressive resistance exercise(PRE) program on measures of impairment, activity, and participationfor people with COPD. Longer term outcomes were also examined12 weeks after the intervention concluded. RELEVANCE: Skeletalmuscle weakness is common in people with COPD and associatedwith reduced exercise tolerance, higher health care utilisation, andpoorer prognosis. Whilst improvements in muscle strength have beendemonstrated after PRE, it is unclear how increases in musclestrength influence functional performance or long-term outcomes.In addition, the feasibility of PRE programs conducted at home orwith equipment other than weight machines is not known in thispopulation. PARTICIPANTS: Fifty-four people (33 women, meanage = 67.7 ±8.6 years) with moderately severe COPD (meanFEV1%predicted = 51 ±23%) were recruited from four hospitals.Inclusion criteria required no pulmonary rehabilitation in the previous12 months. Participants were excluded if they had unstable medicalconditions. METHODS: A single-blind randomised controlled trial inconjunction with qualitative interviews was undertaken. Participantswere randomly allocated into a PRE (n = 27) or no-interventiongroup (n = 27).The PRE group completed three sessions per week(one supervised, two home-based) for 12 weeks. Six exercises wereperformed at an intensity of three sets of 8'12 repetition maximum,progressed against graduated elasticised resistance bands. Majoroutcomes included muscle strength, six-minute walk distance,grocery-shelving task, Chronic Respiratory Disease Questionnaire,and Patient-Specific Functional Scale. Measures were assessedat baseline, post-intervention (12 weeks) and 12 weeks after theintervention (24 weeks). The PRE group were invited to participatein interviews regarding the outcomes of training at 12 and 24 weeks.ANALYSIS: Two-way ANOVA for repeated measures, with andwithout intention-to-treat analysis, were used to examine changesoccurring between 0'12 and 0'24 weeks. Interview data were audiotaped,transcribed, and then coded by two independent researchers.RESULTS: The PRE program was completed by 15 out of 27participants. Participants completing PRE demonstrated improvedmuscle strength (27'46%), dyspnoea, and fatigue levels at 12weeks when compared with no-intervention, but the benefits haddissipated by 24 weeks. No differences were detected betweengroups for measures of activity or participation, or when all outcomeswere examined using intention-to-treat analysis. People with COPDperceived physical, psychological, and social benefits after PRE,which had a positive effect on activity performance. The perceivedphysical benefits of PRE were not prominent at 24 weeks, but feelingsof increased confidence and control persisted.