Over the last decade, investigators have given increased attention to the effects of resistance training (RT) on several metabolic syndrome variables. The metabolic consequences of reduced muscle mass, as a result of normal aging or decreased physical activity, lead to a high prevalence of metabolic disorders. The purpose of this review is: (i) to perform a meta-analysis of randomized controlled trials (RCTs) regarding the effect of RT on obesity-related impaired glucose tolerance and type 2 diabetes mellitus; and (ii) to investigate the existence of a dose-response relationship between intensity, duration and frequency of RT and the metabolic clustering. In the 13 RCTs included in the analysis, RT reduced glycosylated haemoglobin (HbA1c) by 0.48%, fat mass by 2.33 kg and systolic blood pressure by 6.19 mmHg. There was no statistically significant effect of RT on total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride and diastolic blood pressure.
Based on this meta-analysis, RT has a clinically and statistically significant effect on metabolic syndrome risk factors such as obesity, HbA1c levels and systolic blood pressure, and therefore should be recommended in the management of type 2 diabetes and metabolic disorders.