The effects of high-intensity interval training on glucose regulation and insulin resistance: a meta-analysis.
The aim of this meta-analysis was to quantify the effects of high-intensity interval training (HIIT) on markers of glucose regulation and insulin resistance compared with control conditions (CON) or continuous training (CT). Databases were searched for HIIT interventions based upon the inclusion criteria: training ≥2 weeks, adult participants and outcome measurements that included insulin resistance, fasting glucose, HbA1c or fasting insulin. Dual interventions and participants with type 1 diabetes were excluded. Fifty studies were included. There was a reduction in insulin resistance following HIIT compared with both CON and CT (HIIT vs. CON: standardized mean difference [SMD] = -0.49, confidence intervals [CIs] -0.87 to -0.12, P = 0.009; CT: SMD = -0.35, -0.68 to -0.02, P = 0.036). Compared with CON, HbA1c decreased by 0.19% (-0.36 to -0.03, P = 0.021) and body weight decreased by 1.3 kg (-1.9 to -0.7, P < 0.001). There were no statistically significant differences between groups in other outcomes overall. However, participants at risk of or with type 2 diabetes experienced reductions in fasting glucose (-0.92 mmol L(-1), -1.22 to -0.62, P < 0.001) compared with CON. HIIT appears effective at improving metabolic health, particularly in those at risk of or with type 2 diabetes. Larger randomized controlled trials of longer duration than those included in this meta-analysis are required to confirm these results.
Diabetes Research Centre, University of Leicester, Leicester, UK.|NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity Biomedical Research Unit, Leicester & Loughborough, UK.
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Jelleyman
Diabetes Research Centre, University of Leicester, Leicester, UK.|NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity Biomedical Research Unit, Leicester & Loughborough, UK.
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T
Yates
Diabetes Research Centre, University of Leicester, Leicester, UK.
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O'Donovan
Department of Health Sciences, University of Leicester, Leicester, UK.
L J
LJ
Gray
NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity Biomedical Research Unit, Leicester & Loughborough, UK.|School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
J A
JA
King
Diabetes Research Centre, University of Leicester, Leicester, UK.|NIHR Collaboration for Leadership in Applied Health Research and Care - East Midlands (NIHR CLAHRC - EM), Leicester, UK.
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K
Khunti
Diabetes Research Centre, University of Leicester, Leicester, UK.|NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity Biomedical Research Unit, Leicester & Loughborough, UK.
M J
MJ
Davies
D050218:Body Fat Distribution; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000517:prevention & control*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance; D009765:Obesity / Q000378:metabolism / Q000517:prevention & control*; D018384:Oxidative Stress; D010101:Oxygen Consumption; D010809:Physical Fitness; D055070:Resistance Training; D016896:Treatment Outcome
D005947:Glucose
High-intensity interval training; physical activity; type 2 diabetes; weight loss