NEW ORLEANS — Modes of aerobic exercise include cycling, aerobic classes, dancing, calisthenics, jumping rope, swimming, running, and walking. Resistance training comes in a variety of forms, such as using weights, elastic bands, and body weight exercises.
With either mode of exercise, there is a commonality, as to each form’s ability to regulate systemic glucose (blood sugar) balance, skeletal muscle transport, and glucose metabolism.
Glucose is stored in the liver and muscles as glycogen. Glycolysis is the process in which one molecule of glucose is broken down to form two molecules of pyruvate, while glucose storage is referred to a glycogen synthesis.
Regulation of glucose balance – homeostasis – is tightly controlled to provide fasted glucose levels at <100 mg/dl, glycated hemoglobin A1c levels at <5.7%, and blood glucose post prandial (after a meal or challenge) at <140 mg/dl.
According to Regulation of Skeletal Muscle Glucose Transport and Glucose Metabolism by Exercise, which appeared in the October 2019 issue of the online journal Nutrients, “in the fasted state, the liver maintains systemic glucose homeostasis via glycogenolysis (glycogen breakdown) and gluconeogenesis (glucose synthesis).”
“In the fed state, glucose released from the digestive system into the bloodstream causes a rise in blood glucose levels that triggers an increase in insulin production and release from the β-cells of the pancreas.”
Glycogenolysis - the breakdown of glycogen to glucose, which takes place in the cells of the muscles and liver - is initiated by hormonal or neural signals.
Gluconeogenesis, on the other hand, is the metabolic process by which organisms produce sugar (glucose) for catabolic breakdown from non-carbohydrate sources – potentially lean muscle - with illness, overtraining, and other such carbohydrate depleting situations.
Research has demonstrated the profound effect aerobic exercise has on its ability to improve systemic glucose control in individuals with type 2 diabetes.
The Nutrient journal researchers from East Carolina University, comment that, “type 2 diabetes is a chronic metabolic disease characterized by a dysregulation of systemic glucose homeostasis. It is diagnosed when fasted blood glucose levels are >126 mg/dL, HbA1c levels are >6.5%, and blood glucose levels are >200 mg/dL 2 hrs. following an oral glucose challenge.”
While the exact causes of type 2 diabetes remain incompletely understood, note the researchers, “numerous studies have linked impairments in key glucoregulatory functions in the pathogenesis of the disease.”
The East Carolina team state that, “studies in both men and women with type 2 diabetes have demonstrated the following beneficial effects: (1) 8 weeks of aerobic walking (30 min/day, 3 days/week) decreased HbA1c levels ~18%; (2) 12 weeks of bicycle training (60 min/day, 3 days/week) decreased fasted blood glucose levels ~14%; (3) 16 weeks of cardiovascular machine-based training (60 min/day, 3 days/week at 60–65% max heart rate) decreased fasted blood glucose levels ~10% and HbA1c levels ~1%.
Resistance training has also demonstrated improvement in glucose in individuals with type 2 diabetes. The researchers provide evidence that, “8 weeks of progressive free weight and weight machine training involving arms and legs (2 days/week, 7 exercises/session, 3 sets of 10 repetitions at 60% 1 repetition max up to 100% of initial 1 repetition max) decreased HbA1c levels ~18%; (2) 16 weeks of weight machine training involving arms and legs (3 days/week, 5 exercises/session, 8 repetitions at 60–80% max, up to 8 repetitions at 70–80% max) reduced HbA1c levels ~13%.”
It was concluded that aerobic exercise and resistance training ameliorate hyperglycemia (elevated blood sugar), which has to do in part with the positive training-stimulus associated alterations in skeletal muscle glucose transport and glucose metabolism.
It's important to work with your physician, if you have type 1 or 2 diabetes, to make sure that your medication usage, if any, is factored into your exercise routine.
► Get breaking news from your neighborhood delivered directly to you by downloading the new FREE WWL-TV News app now in the IOS App Store or Google Play.
