Exercise in type 2 diabetes: genetic, metabolic and neuromuscular adaptations. A review of the evidence

Abstract

The biological responses to exercise training are complex, as almost all organs and systems are involved in interactions that result in a plethora of adaptations at the genetic, metabolic and neuromuscular levels.To provide the general practitioner and the sports medicine professionals with a basic understanding of the genetic, metabolic and neuromuscular adaptations at a cellular level that occur with aerobic and resistance exercise in subjects with type 2 diabetes.For each of the three domains (genetic, metabolic and neuromuscular), the results of the major systematic reviews and original research published in relevant journals, indexed in PubMed, were selected. Owing to limitations of space, we focused primarily on the role of skeletal muscle, given its pivotal role in mediating adaptations at all levels.Generally, training-induced adaptations in skeletal muscle are seen as changes in contractile proteins, mitochondrial function, metabolic regulation, intracellular signalling, transcriptional responses and neuromuscular modifications. The main adaptation with clinical relevance would include an improved oxidative capacity derived from aerobic training, in addition to neuromuscular remodelling derived from resistance training. Both training modalities improve insulin sensitivity and reduce cardiovascular risk.Taken together, the modifications that occur at the genetic, metabolic and neuromuscular levels, work correlatively to optimise substrate delivery, mitochondrial respiratory capacity and contractile function during exercise.

Beyond general resistance training. Hypertrophy versus muscular endurance training as therapeutic interventions in adults with type 2 diabetes mellitus: A systematic review and meta‐analysis

“…The main adaptations induced by RT and AT in patients with T2DM are well‐known . Overall, RT improves insulin sensitivity and glucose tolerance, while improving strength parameters and slightly cardiorespiratory fitness (CRF), whereas AT induces significant benefits on CRF and metabolic control .…”

“…Nevertheless, equivocal findings and discrepancies regarding the effects of RT in T2DM exist (Appendix 1). Of note, it seems that the most frequent RT employed for the management of T2DM (hypertrophy training [HT] and muscular endurance training [MERT]) might induce similar beneficial effects on metabolic control via different but interconnected qualitative/quantitative alterations in the skeletal muscle . However, there is no previous meta‐analytic evidence regarding the effectiveness of HT and MERT (different stimuli characterized by specific doses of exercise) in T2DM.…”

Concurrent exercise training on hyperglycemia and comorbidities associated: Non‐responders using clinical cutoff points

“…Many of the cardiometabolic risk factors associated with T2DM can be improved or ameliorated with weight control and diet, as well as with regular exercise. Indeed, the beneficial effects of high‐intensity interval (HIIT) and resistance (RT) training on insulin resistance have been extensively studied at the level of skeletal muscle and adipose tissue . In this regard, HIIT has become an increasingly popular training modality for reducing such risk factors, based on a number of metabolic improvements, including fat reduction, increased lipid oxidation, and improved insulin sensitivity .…”

“…Indeed, the beneficial effects of high-intensity interval (HIIT) and resistance (RT) training on insulin resistance have been extensively studied at the level of skeletal muscle and adipose tissue. 8 In this regard, HIIT has become an increasingly popular training modality for reducing such risk factors, based on a number of metabolic improvements, including fat reduction, increased lipid oxidation, and improved insulin sensitivity. 9 Accordingly, HIIT can decrease 24-hour average glucose concentration by −13% on average, 2 fasting glucose ~14%, 10 waist circumference (WC, −2.4 cm), 11 fat mass −5.6%, 12 or systolic blood pressure (SBP, −6 mm Hg) 11 in adults with poor glucose control.…”

Divergent Energy Expenditure Impacts Mouse Metabolic Adaptation to Acute High-Fat/High-Sucrose Diet Producing Sexually Dimorphic Weight Gain Patterns

“…Improved energy balance at higher physical activity levels is 34 proposed to be achieved through greater coupled sensitivity of energy intake regulation to 35 energy expenditure [6,8]. However, increased physical activity produces multiple systemic and 36 tissue-specific adaptations independent of EE (reviewed in [19][20][21]), complicating the direct 37 investigation of modulating EE to protect against diet-induced weight gain. Additionally, 38 observed sex differences in physical activity levels and physiological adaptation may impact 39 weight gain prevention and/or obesity treatment [22,23].…”