Effects of resistance training on muscle strength in adults with haemophilia: A systematic review and meta-analysis

Introduction: Although resistance training is frequently prescribed for people with haemophilia (PWH), no previous meta-analyses have quantified the effect of this intervention on muscle strength, nor the implications of the intervention's modality and duration.

Aim: (1) To determine the effects of resistance training on muscle strength in adults with haemophilia; (2) To determine the most effective duration and modality among the exercise protocols.

Methods: A systematic search from inception until 28 November 2023 was conducted in PubMed, Embase, Web of Science, CENTRAL and CINAHL databases. We included randomised controlled trials or before-after studies that involved resistance training without other physiotherapy co-interventions. Study selection, data extraction and risk of bias assessment were independently performed by two reviewers. Disagreements were resolved in consultation with a third author. The level of evidence was determined according to the GRADE methodology.

Results: Seven studies were included. Measurements of knee extensor strength and elbow extensor strength were included in the meta-analysis. Subgroup analysis showed significant effects for both elastic resistance protocols (SMD: 0.54; 95% CI: 0.02-1.07) and conventional training (isometric and weight-based equipment) (SMD: 0.88; 95% CI: 0.50-1.25), demonstrating small and moderate effect sizes respectively. Additionally, both protocols of duration 5-7 weeks (SMD: 1.16, 95% CI: 0.63-1.69) as well as those of duration ≥8 weeks (SMD: 0.57, 95% CI: 0.20-0.94) showed a significant difference.

Conclusion: Resistance training is effective in improving muscle strength of the knee and elbow extensors in PWH. Both elastic resistance and conventional training show benefits.