New Study Reveals the Benefits of Preoperative High-Intensity Interval Training for Cardiorespiratory Health

In a recent systematic review and meta-analysis, researchers have found evidence suggesting that preoperative high-intensity interval training (HIIT) can enhance cardiorespiratory fitness (CRF) and decrease postoperative complications.

Previous studies have already demonstrated that HIIT, which involves alternating short bursts of intense aerobic exercise with active recovery periods, can improve CRF. The authors of the study, published in JAMA Network Open, highlighted the appeal of HIIT for preoperative patients, as it can effectively increase CRF even in individuals with various health conditions, ages, and comorbidities.

The research team from the University of Otago in New Zealand conducted a comprehensive analysis to summarize existing data on the association between preoperative HIIT and preoperative CRF, as well as postoperative outcomes, including complications, hospital length of stay (LOS), and patient quality of life.

To gather relevant information, the researchers searched several databases for randomized clinical trials and prospective cohort studies involving HIIT protocols in adults undergoing major surgery. The primary focus was on changes in CRF, measured by either peak oxygen consumption (V̇o2 peak) or 6-Minute Walk Test distance.

The analysis identified 12 eligible studies involving 832 patients. The average age of participants was 66.5 years in the intervention group and 67.1 years in the control group, with a majority of male participants in both groups (59.7% and 65.4%, respectively). Overall, the pooled results indicated several positive associations between HIIT and both CRF improvement and postoperative outcomes.

Among the findings, researchers observed moderate-quality evidence of significant improvement in V̇o2 peak in 8 studies comprising 627 patients (cumulative mean difference 2.59mL/kg/min, 95% CI 1.52-3.65; P<.001). Additionally, in 8 studies involving 770 patients, there was moderate evidence suggesting that preoperative HIIT reduced the odds of postoperative complications by 56% (odds ratio 0.44, 95% CI 0.32-0.60; P<.001).

However, the analysis did not reveal any evidence indicating a difference between HIIT and standard care regarding hospital LOS (cumulative mean difference -3.06 days, 95% CI -6.41 to 0.29 days; P=.07).

The researchers noted a low risk of bias overall, but they also identified a high degree of heterogeneity in the study outcomes. This finding highlights the necessity for further well-designed studies to improve the quality of evidence and confirm the effectiveness of HIIT protocols.

While the review and meta-analysis have some limitations, such as study heterogeneity, incomplete reporting of findings, limited sample size, and lack of participant masking, the results indicate that preoperative HIIT may be beneficial for surgical populations. The improvement in exercise capacity and reduction in postoperative complications support the inclusion of HIIT in prehabilitation programs before major surgery, as concluded by the study authors.