Cycle ergometer and inspiratory muscle training offer modest benefit compared with cycle ergometer alone: a comprehensive assessment in stable COPD patients

Abstract

BackgroundCycle ergometer training (CET) has been shown to improve exercise performance of the quadriceps muscles in patients with COPD, and inspiratory muscle training (IMT) may improve the pressure-generating capacity of the inspiratory muscles. However, the effects of combined CET and IMT remain unclear and there is a lack of comprehensive assessment.Materials and methodsEighty-one patients with COPD were randomly allocated to three groups: 28 received 8 weeks of CET + IMT (combined training group), 27 received 8 weeks of CET alone (CET group), and 26 only received 8 weeks of free walking (control group). Comprehensive assessment including respiratory muscle strength, exercise capacity, pulmonary function, dyspnea, quality of life, emotional status, nutritional status, and body mass index, airflow obstruction, and exercise capacity index were measured before and after the pulmonary rehabilitation program.ResultsRespiratory muscle strength, exercise capacity, inspiratory capacity, dyspnea, quality of life, depression and anxiety, and nutritional status were all improved in the combined training and CET groups when compared with that in the control group (P<0.05) after pulmonary rehabilitation program. Inspiratory muscle strength increased significantly in the combined training group when compared with that in the CET group (ΔPImax [maximal inspiratory pressure] 5.20±0.89 cmH2O vs 1.32±0.91 cmH2O; P<0.05). However, there were no significant differences in the other indices between the two groups (P>0.05). Patients with weakened respiratory muscles in the combined training group derived no greater benefit than those without respiratory muscle weakness (P>0.05). There were no significant differences in these indices between the patients with malnutrition and normal nutrition after pulmonary rehabilitation program (P>0.05).ConclusionCombined training is more effective than CET alone for increasing inspiratory muscle strength. IMT may not be useful when combined with CET in patients with weakened inspiratory muscles. Nutritional status had slight impact on the effects of pulmonary rehabilitation. A comprehensive assessment approach can be more objective to evaluate the effects of combined CET and IMT.

Effects of inspiratory muscle training in COPD patients: A systematic review and meta‐analysis

“…Dyspnea at the end of 6MWT was decreased in all studies but was clinically relevant in only two studies …”

“…Two thousand and fifty‐seven articles were identified but only 43 studies (38 RCT, 2 CT, and 3 cohort studies) were included in the systematic review and 37 out of them in the meta‐analysis. Reasons for study exclusion are outlined in Figure …”

“…During PR, five authors used dyspnea as outcome . In all studies, dyspnea was decreased after PR program with or without IMT.…”

“…The authors of all studies without one study reported relevant improvement (reduction of at least four points in SGRQ or increase of more than 0.5 per item of CRQ) …”

“…Since 1996, four randomized trials and one controlled trial evaluated benefit on dyspnea of adding IMT to pulmonary rehabilitation. In all studies, dyspnea was decreased after PR program with or without IMT.…”