RATIONALE: Levels of physical activity and physical fitness are low after stroke. Low muscle strength is common, particularly on the affected side, and is associated with post-stroke disability. Resistance training exercise interventions could increase muscle strength, improve physical function and reduce disability, and may benefit secondary prevention.
OBJECTIVES: The primary objective of this review is to determine whether resistance training after stroke has any effects on death, disability, adverse events, risk factors, fitness, walking, and indices of physical function when compared to a non-exercise control.
SEARCH METHODS: In January 2024, we searched nine databases (CENTRAL, MEDLINE, Embase, CINAHL, SPORTDiscus, PsycINFO, WoS, PEDro and DORIS) and two trial registers (ClinicalTrials.gov and ICTRP), together with reference checking, citation tracking and contact with experts in the field, to identify eligible studies.
ELIGIBILITY CRITERIA: We included randomised controlled trials comparing resistance training interventions with comparators of either usual care, no intervention, or a non-exercise intervention in people with stroke.
OUTCOMES: Our critical outcome domains were death, disability, adverse events, risk factors, fitness, walking and indices of physical function. We assessed outcomes at the end of intervention and at the end of the longest follow-up. Our other important outcome domains were indices of quality of life, mood, cognition and fatigue.
RISK OF BIAS: We used the Cochrane Risk of Bias 1.0 tool to assess bias in the included studies.
SYNTHESIS METHODS: Where possible, we synthesised results for each outcome at the end of the intervention and at the end of follow-up using random-effects meta-analyses on arm-level data. For dichotomous outcomes, we calculated the risk difference (RD) and 95% confidence interval (CI). For continuous outcomes, we calculated a mean difference (MD), or standardised mean difference (SMD), and 95% CI. For outcomes not analysed using meta-analysis, we followed the Synthesis Without Meta-analysis (SWiM) guidance. We used GRADE to assess the certainty of evidence for critical outcomes.
INCLUDED STUDIES: We included a total of 27 studies with 1004 participants, with an average age of 62 years. Most studies recruited ambulatory participants (18/27) during the sub-acute (10/27) and chronic (16/27) stages of recovery living in high-income countries (18/27). Most study interventions lacked a balanced dose of control exposure (17/27). A follow-up period was included in 8/27 studies (mean 9.9 months; range 2 to 48 months). Interventions typically involved exercise machines (16/27) or bodyweight exercises (10/27) delivered two to three days per week for between two and 12 weeks, which progressed on the basis of intensity and/or volume.
SYNTHESIS OF RESULTS: Resistance training does not increase (or decrease) deaths at the end of intervention (risk difference RD 0.00, 95% CI -0.02 to 0.02; I² = 0%; 24 studies, 880 participants; high-certainty) or follow-up (RD 0.00, 95% CI -0.05 to 0.05; I² = 0%; 5 studies, 202 participants; high-certainty). The evidence is very uncertain about the effect of resistance training on indices of disability at the end of intervention (standardised mean difference SMD 0.55, 95% CI -0.24 to 1.33; 1 study, 26 participants; very low-certainty). There is a moderate-sized effect (SMD > 0.5) but there was only one small study. No data were available at follow-up. Resistance training may have little or no effect on the incidence of secondary cardiovascular or cerebrovascular events (all-cause) at the end of intervention (RD 0.00, 95% CI -0.31 to 0.31; 1 study, 10 participants; very low-certainty). There was only one small study. No data were available at follow-up. Resistance training may reduce systolic blood pressure (mmHg) at the end of intervention, but the evidence is very uncertain (mean difference MD -5.00, 95% CI -34.42 to 24.42; 1 study, 22 participants; very low-certainty). There was only one small study. No data were available at follow-up. Resistance training probably improves multiple indices of musculoskeletal fitness at the end of intervention (overall moderate-certainty). Improvements in muscle strength occurred in the legs on the affected (moderate effect SMD > 0.5) and least affected sides (large effect SMD > 0.8), and both arms (moderate effect SMD > 0.5) although the evidence is less certain on the affected arm. Overall, there were very few data at the end of follow-up and overall effects were very uncertain. Resistance training probably results in little or no beneficial effect on comfortable walking speed (m/sec) at the end of intervention (MD -0.00, 95% CI -0.08 to 0.07; I² = 43%; 6 studies, 212 participants; moderate-certainty) or the end of follow-up (MD 0.12, 95% CI -0.02 to 0.26; 1 study, 93 participants; low-certainty). Resistance training may improve indices of balance slightly (small effect SMD > 0.2) at the end of intervention (SMD 0.45, 95% CI 0.09 to 0.80; I² = 24%; 5 studies, 190 participants; low-certainty) and end of follow-up (SMD 0.44, 95% CI 0.03 to 0.85; 1 study, 93 participants; low-certainty). There was no evidence concerning adverse effects attributable to participating in resistance training interventions. Adherence was good, although there were some dropouts attributable to the resistance training intervention. Overall, evidence certainty was limited by imprecision and risk of bias concerns.
AUTHORS' CONCLUSIONS: Resistance training does not affect mortality at the end of intervention or after follow-up. We could not draw conclusions about resistance training effects on disability, secondary prevention of cardiovascular or cerebrovascular events or the risk of these because the data were inadequate. Resistance training probably increases muscle strength in the arms and legs, particularly on the unaffected side at the end of intervention. There was little or no effect on comfortable walking speed, possibly because the interventions were insufficiently task-related to walking. However, there may be a small improvement in balance which persists at follow-up. Resistance training interventions were adhered to without serious adverse events or adverse effects, but may not be acceptable to everyone. Inadequate data at follow-up prevented conclusions about retention of benefits. Further well-designed randomised trials are needed to determine the optimal exercise prescription, the benefits and long-term effects.
FUNDING: This Cochrane review had no dedicated funding.
REGISTRATION: Protocol [and previous versions] available via DOI 10.1002/14651858.CD003316 [DOI/10.1002/14651858.CD003316.pub7, DOI/10.1002/14651858.CD003316.pub6, DOI/10.1002/14651858.CD003316.pub5, DOI/10.1002/14651858.CD003316.pub4, DOI/10.1002/14651858.CD003316.pub3, DOI/10.1002/14651858.CD003316.pub2].
