The feasibility, safety, physiological and clinical effects of high-intensity interval training for people with Parkinson’s: a systematic review and meta-analysis

Background Exercise is important for people with Parkinson’s (PwP), with high-intensity interval training (HIIT) proposed as a feasible and effective exercise modality. However, no literature synthesis for PwP has been undertaken. Objectives To evaluate the feasibility, safety, physiological and clinical effects of HIIT for PwP. Methods Systematic searches of Medline, Embase, CINAHL, Web of Science, and Google Scholar were undertaken. Studies that included ≥ 2 weeks of HIIT for PwP and reported sufficient detail for full quality assessment were eligible. Quality was assessed with the TESTEX scale or the Downs and Black tool according to study design. Feasibility and safety data, physiological and clinical outcomes were extracted. Meta-analyses explored the pooled effects of HIIT on VO 2peak/max compared to moderate-intensity continuous exercise (MICE) and usual care. Results Eleven articles were identified (seven controlled/comparator studies and four single group) including 117 HIIT participants predominantly of mild-to-moderate disease severity. HIIT programmes were professionally supervised and between 6 weeks and 24 months. Overall, study quality was deemed to be moderate to good. Following screening, nine studies reported 90–100% programme completion; however, only one was > 12 weeks in duration. Adverse events were uncommon. HIIT improved VO 2peak/max compared to usual care, but not to MICE. Increased brain-derived neurotrophic factor (BDNF) and improved motor symptoms were also reported. Conclusion Up to 12 weeks of supervised HIIT appears to be feasible and safe for some people with mild-to-moderate disease severity. HIIT improves cardiorespiratory fitness and may increase BDNF and improve motor symptoms in PwP. Future studies should explore safe ways to facilitate access and long-term adherence.