Clinical updates on the effects of high intensity interval training (HIIT) exercise in people diagnosed with cancer. A systematic review and meta-analysis

Objectives: To provide an updated critical evaluation on the effectiveness of high intensity interval training (HIIT) on health outcomes amongst cancer survivors.Design: Systematic review and meta-analysis.Methods: A systematic search was conducted using databases CINAHL and Medline (via EBSCOhost platform), Scopus, Web of Science Core Collection, and the Cochrane Central Register of Controlled Trials. Randomised, controlled, exercise trials involving cancer survivors were eligible. Data on the effects of HIIT amongst individuals diagnosed with cancer at any stage were included. Risk of bias was assessed with the Mixed Methods Appraisal Tool (MMAT). Standardised mean differences (SMD) were calculated to compare differences between exercise and usual care. Meta-analyses (including subgroup analyses) were undertaken on the primary outcome of interest, which was aerobic fitness. Secondary outcomes were fatigue, quality of life, physical function, muscle strength, pain, anxiety, depression, upper-body strength, lower-body strength, systolic and diastolic blood pressure.Results: Thirty-five trials from forty-seven publications were included, with intervention durations ranging between 4 and 18 weeks. Breast cancer participants were represented in the highest number of trials (n = 13, 37 %). Significant effects in favour of HIIT exercise for improving aerobic fitness, quality of life, pain and diastolic blood pressure were observed (SMD range: 0.25-0.58, all p < 0.01).Conclusions: Participation in HIIT exercise was associated with higher retention and improvements in aerobic fitness, quality of life, pain and diastolic blood pressure. The present results provide updated contemporary evidence for clinicians (e.g., exercise physiologists and physiotherapists) to prescribe HIIT exercise for cancer survivors to improve health before, during and following treatment.(c) 2023 The Authors. Published by Elsevier Ltd on behalf of Sports Medicine Australia. This is an open access article