The Effect of High-Intensity Interval Training on Visceral Adipose Tissue in Type 2 Diabetes: A Systematic Review.

Visceral adipose tissue (VAT) is a significant contributor to insulin resistance in type 2 diabetes (T2D). The effectiveness of time-efficient high-intensity interval training (HIIT) in reducing VAT has not been reviewed. A systematic search conducted on PubMed, Embase, and SPORTDiscus up to April 2025 for randomized controlled trials that compared HIIT with non-exercise control and quantified VAT using imaging identified five trials (n = 138) that met inclusion criteria. Risk of bias was assessed using a nine-item modified PEDro scale. Four trials reported significant reductions in VAT after 8-12 weeks of thrice-weekly cycling HIIT sessions. Furthermore, all five HIIT interventions showed significant reductions in glycosylated hemoglobin compared to the control groups. Overall, supervised HIIT appears effective, resulting in clinically significant reductions in VAT and glycemic control. Nonetheless, these conclusions are limited by small sample sizes, protocol heterogeneity, and short follow-up durations. Larger trials that standardize interval structures, evaluate unsupervised adherence, and investigate mechanistic mediators are necessary to confirm the sustainability of outcomes and inform clinical applications of HIIT for patients with T2D.