3.16 Insulin Resistance & Muscle Mass

Insulin resistance is generally accepted as the dominant factor leading to type 2 diabetes, and the most probable single link between obesity, type 2 diabetes and cardiovascular disease [1].

A hallmark of T2 diabetes is metabolic inflexibility. Metabolic flexibility is a measure of the body’s ability to respond or adapt to conditional changes in metabolic demand, insulin resistance, and the mechanisms that govern energy selection between glucose and fatty acids [1].

Insulin resistance is a key component of the metabolic inflexibility that can develop in many tissues and organs. Recently, research on the mechanisms underlying insulin resistance in liver and skeletal muscle [impaired mitochondrial fatty acid oxidation and excess accumulation of lipid metabolites] points to the importance of regular exercise [2].

Apart from medication, regular exercise is a proven prevention and treatment strategy for individuals with pre-diabetes and T2D [2]. A consistent regimen of resistance training (RT) and endurance training (ET) promotes health benefits through increases in muscle mass that positively impact insulin responsiveness and glucose control. Exercise recommendations ideally combine RT and ET training with to achieve gains in muscle mass as well as reducing circulating pro-inflammatory cytokines to achieve metabolic health.

1. Goodpaster BH, Sparks LM. Metabolic Flexibility in Health and Disease. Cell Metab. 2017 May 2;25(5):1027-1036. doi: 10.1016/j.cmet.2017.04.015. PMID: 28467922; PMCID: PMC5513193.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5513193/#R100

2. Pesta DH, Goncalves RLS, Madiraju AK, Strasser B, Sparks LM. (2017). Resistance training to improve type 2 diabetes: working toward a prescription for the future. Nutr Metab (Lond). doi: 10.1186/s12986-017-0173-7. PMID: 28270856; PMCID: PMC5335813.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5335813/