Effects of respiratory muscle training on respiratory function, exercise capacity, and quality of life in chronic stroke patients: a systematic review and meta-analysis

Lang Huang¹Jia-Mei Zhang²Zi-Ting Bi¹Jing-Hua Xiao¹Jing-Xue Wei¹Jian Huang³Chao-Song Luo³Ying-Dong Li⁴Yue-Mi Zhang⁴Yun-shan Zhang^1*

• ¹Department of Rehabilitation Medicine, First Affiliated Hospital, Guangxi Medical University, Nanning, China
• ²Department of Rehabilitation Medicine, Guangxi International Zhuang Medicine Hospital, Nanning, China
• ³Cardiopulmonary Rehabilitation Center, Jiangbin Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
• ⁴Department of Rehabilitation Medicine, The Guangxi Zhuang Autonomous Region Workers’ Hospital, Guangxi, China

The study evaluated the influence of respiratory muscle training on respiratory function, exercise capacity and quality of life in chronic stroke patients. A comprehensive search of six databases was conducted without any limitations on date, extending until March 8, 2025. The search targeted randomized controlled trials that involved: 1) chronic stroke patients (≥18 years, diagnosed for >3 months), 2) respiratory muscle training encompasses both inspiratory and expiratory muscle trainings, and 3) outcomes measuring the strength and endurance of respiratory muscle, pulmonary function testing, exercise capacity, and quality of life. Two separate reviewers conducted the screening for eligibility, gathered data, and evaluated both the methodological quality and potential risk of bias. Meta-analyses utilized RevMan version 5.4, applying random-effects models to calculate mean differences (MD), standardized mean differences (SMD), and corresponding 95% confidence intervals (95% CI). Nine studies (288 participants, mean age 58.5 years) were included. Respiratory muscle training significantly enhanced maximal inspiratory pressure (MD=17.71, 95% CI: 10.19-25.23), respiratory muscle endurance (MD=20.58, 95% CI: 12.25-28.92), forced expiratory volume in 1s (MD=0.25, 95%CI: 0.06-0.44), and peak expiratory flow (MD=0.84, 95% CI: 0.31-1.37) among chronic stroke patients. However, no significant effects were observed for maximal expiratory pressure (MD=11.37, 95% CI: -0.78 to 25.23), forced vital capacity(MD=0.16, 95% CI: -0.08-0.41), exercise capacity (SMD=0.29, 95% CI: -0.03-0.61), and quality of life. The subgroup analysis revealed that the combination of inspiratory muscle training and expiratory muscle training enhanced maximal inspiratory pressure (MD=23.47, 95% CI:3.65-43.30) and respiratory muscle endurance (MD=34.00, 95% CI: 21.21-46.79), while inspiratory muscle training improved maximal inspiratory pressure (MD=14.09, 95% CI: 7.57-20.62), maximal expiratory pressure (MD=8.69, 95%CI: 0.63-16.75), and respiratory muscle endurance (MD=16.69, 95% CI: 10.27-23.11). Respiratory muscle training effectively enhances maximal inspiratory pressure, respiratory muscle endurance, forced expiratory volume in 1s, and peak expiratory flow among chronic stroke patients but does not improve maximal expiratory pressure, forced vital capacity, exercise capacity, and quality of life. The combination of inspiratory muscle training with expiratory muscle training, as well as inspiratory muscle training alone, can enhance maximal inspiratory pressure and respiratory muscle endurance.Inspiratory muscle training alone can improve maximal expiratory pressure.