Authors (including presenting author) :
Stephen CHAN WW (1), Henry PAK CH (2)
Affiliation :
1) Allied Health Department, Hong Kong Children’s Hospital 2) MCSP, HCPC-Registered Physiotherapist, Priory Hospital Bristol
Introduction :
High-intensity interval training (HIIT) has emerged as an effective exercise modality for improving health outcomes in patients with type 2 diabetes (T2D). This systematic review analyzes HIIT program parameters reported in randomized controlled trials that demonstrated favorable effects on glycemic control and cardiorespiratory fitness.
Objectives :
The aim is to provide clinicians with evidence-based recommendations for HIIT exercise prescriptions in managing T2D.
Methodology :
A comprehensive literature search was conducted across major databases, including PubMed, Embase, and the Cochrane Library, targeting RCTs involving HIIT in T2D patients. The search utilized the “Patients, Intervention, Comparison, and Outcomes” (PICO) framework: Patients (individuals with T2D), Intervention (HIIT), Comparison (control groups), and Outcomes (glycemic control, body composition, cardiorespiratory fitness). Data on exercise type, intensity, frequency, duration, and mode were extracted. Key outcomes included glycated hemoglobin (HbA1c) levels, body mass index (BMI), and peak oxygen uptake (VO2peak). The methodological quality of included studies was assessed using the PEDro scale, alongside a risk-of-bias evaluation using the Cochrane Collaboration's tool.
Result & Outcome :
The review included 14 trials with 441 participants aged 40-75 years. Results indicated that HIIT significantly enhanced glycemic control, with reductions in HbA1c levels (P<0.0001). Participants engaging in HIIT experienced improved cardiorespiratory fitness, evidenced by higher VO2peak values (P<0.05). The HIIT protocols varied across studies, predominantly featuring aerobic exercises like cycling, running, and walking. The intensity of HIIT sessions typically ranged from 80% to 95% of maximum heart rate, with training frequency between 2 to 5 sessions per week for at least 11 weeks (11-16 weeks). Session durations ranged from 20 to 60 minutes, incorporating high-intensity intervals lasting 30 seconds to 4 minutes, followed by low-intensity recovery. Improvements in body composition were also significant, with notable reductions in body weight, BMI, and body fat percentage (P<0.05). PEDro scores ranged from 6 to 8, indicating moderate to high methodological quality. Most studies showed low to moderate risk of bias, primarily concerning blinding and allocation concealment. Reported adverse events included mild musculoskeletal discomfort and transient fatigue, with no serious incidents, indicating that HIIT is generally safe for patients with T2D when appropriately supervised. Conclusions This systematic review highlights the clinical relevance of HIIT, providing practical, evidence-based insights for enhancing glycemic control and cardiorespiratory fitness in patients with T2D. HIIT is a time-efficient, effective alternative for lifestyle management in patients with T2D, supported by a favorable safety profile.
