This article will talk about the correlation between physical activity and type 2 diabetes. We will briefly overview the pathology, mentioning the causes, consequences, and possible treatments.
Later, we will go into the details of the dedicated physical therapy, mentioning the types and methods to intervene in the case of type 2 diabetes.
What Is Type 2 Diabetes?
Type 2 diabetes is a metabolic disorder characterized by chronic hyperglycemia (excess glucose in the plasma ) based on two pathological mechanisms:
- Insulin resistance: a lack of insulin effect on peripheral tissues.
- Insulin synthesis deficiency: reduced production of the hormone by the pancreas.
Note: Insulin synthesis deficiency is often a long-term complication of insulin resistance.
It occurs mainly in adults and is the most common form of diabetes (90% of cases). Unlike type 1, it is not insulin-dependent; although the pancreas stops functioning as it should in severe cases, exogenous insulin therapy may still become necessary.
The causes can be of hereditary or environmental nature; among the latter, obesity stands out, followed by a sedentary lifestyle, an unbalanced diet characterized by excess carbohydrates, stress, other diseases, and certain drugs.
Obesity and Diabetes
Furthermore, in obesity, adipose tissue is the site of chronic low-intensity inflammation, a source of chemical mediators that aggravate insulin resistance.
Type 2 diabetes increases the risk of early death and permanent disability; above all, it seems to increase the cardiovascular risk and in particular dyslipidemia (hypercholesterolemia and hypertriglyceridemia) in association with other pathological forms, such as arterial hypertension.
In the early stage, type 2 diabetes does not always cause noticeable symptoms; on the contrary, it is almost always completely asymptomatic until the first complications arise.
Only a hematological investigation can highlight chronic hyperglycemia, the consequent compensatory hyperinsulinism, and a state of excessive protein glycation. More specific analyzes, such as the load curve, will confirm the diagnosis.
However, chronic hyperglycemia can manifest itself with: fatigue, frequent urination, excessive thirst, difficulty losing weight, unexplained weight loss, slow wound healing, blurred vision.
Treatment of type 2 diabetes should be multidisciplinary. The importance of one aspect can vary depending on the personal situation. Pharmacological use is crucial in restoring general homeostasis in the short term, even if food and physical therapy are the only solutions for type 2 diabetes not complicated by the loss of pancreatic function.
The use of oral hypoglycemic agents is the most common strategy, while insulin administration is limited to cases in which the pancreas has stopped synthesizing it adequately.
In the obese subjects, the diet is aimed above all at fat loss. It is advisable to structure it in a balanced way, keeping the carbohydrate ratio at the lower limit of the normal range. Ketosis can be a significant risk for diabetics with kidney complications.
On the other hand, physical activity and supporting weight loss will increase insulin sensitivity, though one must improve the management of carbohydrates.
Benefits Of Physical Activity On The Diabetic
Physical activity is effective in preventing and treating type 2 diabetes. Exercising positively impacts both acute (while working out) and chronic (in the long term) metabolism.
Among the benefits of training on type 2 diabetes we recognize above all an improvement in insulin sensitivity and an increase in the efficacy of cellular glucose transport, with a reduction in blood sugar, insulin, triglycerides and glycated proteins.
The improvement of insulin sensitivity and the emptying of hepatic and muscle glycogen reserves promote better management of carbohydrates, helping optimize weight loss, increasing insulin sensitivity.
Benefits On Insulin Sensitivity
Insulin resistance compromises the absorption of insulin-mediated glucose, therefore on insulin-dependent tissues, by 35/40% compared to healthy people.
The most abundant insulin-dependent tissue in the body is skeletal muscle, which positively correlates with the ability to absorb glucose, while fat mass has an inverse correlation.
In acute cases, physical activity increases insulin sensitivity for 24-72 hours after training, even in people with type 2 diabetes.
After this period of time, it is necessary to apply a new physical stimulus to restore this advantageous situation. This is why those with type 2 diabetes should train more or less every other day.
Benefits On Glucose Transport
The metabolic use of glucose in muscle fiber cells occurs, very briefly, as follows:
Switching from plasma to muscle tissue – Physical exercise improves blood flow, thanks to more significant cardiovascular action and peripheral capillarization. Good distribution is crucial for meeting the need for glucose, oxygen, and muscles and allows the disposal of waste residues.
Physical exercise also promotes the opening of ordinarily unused capillaries; it stimulates further branching in the chronically affected by type 2 diabetes.
Transport of glucose through the cell membrane – The trans-cellular membrane transport of glucose occurs through glucose transporters 4 (GLUT-4), which are typically found in the intracellular cytosol. Physical training stimulates the latter’s emergence, making the cell more able to capture glucose.
Phosphorylation – The energetic use of glucose occurs thanks to an enzyme called hexokinase, which significantly increases concentration if physical activity is performed regularly over the long term.
During and after exercise, a consistent metabolic activation makes the muscle cells partially independent from the insulin action.
Benefits On The Management Of Carbohydrates
Physical activity makes the body able to manage the glycemic load better. This is due to an adequate emptying of the hepatic and muscle glycogen reserves and the metabolic and functional modifications of the exercise phase.
Benefits Of Physical Activity On Other Risk Factors
Present in over 60% of type 2 diabetics, primary arterial hypertension is the statistically most damaging and dangerous comorbidity. Normal blood pressure ranges are 140/90, borderline between 160/95, and pathological when higher.
Regular physical activity lowers blood pressure levels in healthy people and people with type 2 diabetes, thanks to better cardiovascular efficiency. Hypertension also decreases due to weight loss and reduction of central nervous effects.
The recommended type of training is anaerobic and even a high-intensity one in trained subjects. Weights are not contraindicated unless the Valsalva maneuver is established except for high intensities.
Aerobic exercise reduces triglyceridemia, also as a result of better glycemic management. It also improves cholesterolemia, with an increase in HDL and a percentage reduction in LDL. Total cholesterol does not always decrease but the risk of atherosclerosis and coronary heart disease is also lowered.
Physical activity promotes weight loss only when combined with a low-calorie diet. Conversely, a moderate amount of about 20-30 minutes a day at moderate intensity has more of preventive action on weight gain.
How To Do Resistance Training With Type 2 Diabetes
The diabetic person cannot easily accomplish a training volume of 20/30 minutes a day.
In fact, despite the indications, obesity, osteoarticular pathologies, and complications of various kinds can compromise this goal.
This is why some alternatives have been proposed. First, resistance training is a valuable and safe tool for some chronic diseases, even in the elderly and obese. It too improves insulin sensitivity, increases calorie expenditure, and optimizes the quality of life; it also increases muscle strength, lean mass, and bone mineral density.
The right training load is at least 2-3 days a week, with 8-10 exercises targeting the largest muscle groups, for 1-3 sets of 10-15 repetitions each. Progressive overload must be pursued, with no less than 50% of 1RM.
Guidelines For An Adapted Physical Activity Protocol
With the addition of resistance training, it will be possible to take advantage of the benefits that low-intensity aerobic activity does not by itself confer.
Also, flexibility, elasticity, and joint mobility should not be overlooked. This type of training significantly reduces the risk of injury and improves the general quality of life but does not bring metabolic benefits.
The frequency of recommended physical activity varies from 3 to 5 sessions per week, avoiding periods of inactivity for more than two days in a row for the reasons we have explained above.
No less than 20-30 minutes and up to 60 minutes of activity per workout are recommended. You must add 5-10 minutes of warm-up and 5-10 minutes of cool-down, which you can use for flexibility, elasticity, and mobility protocols.
Aerobic intensity should be low initially, then moderate (40-60% of VO2max or 50-70% of HR max ) for 150-200 minutes per week.
When intensity grows (> 60% of VO2max or> 70% of Fcmax), it is possible to reduce the volume to 90 minutes per week.
Before starting a physical activity program, you should be aware of the precautions before, during, and after the activity.
Glycemic control is the fundamental element to check before starting and during and after physical activity. Avoid undertaking activity if the glycemia is > 250 mg/dl or if ketonuria is present.
Often, improved metabolic fitness makes treatments excessively hypoglycemic. However, light or moderate-intensity may help lower acute blood glucose levels. You should also pay attention to physical activity and drug therapy.
Be mindful of keeping body hydration high.
Physical Activity Guidelines In The Presence Of Complications
The physical activity protocol for subjects with complications must be adapted according to those complications, in particular:
- Ischemic heart disease – Physical activities that produce pain or a strong increase in heart rate should be avoided. At the same time, it is recommended to practice physical activities of low-moderate intensity (40% of Vo2max or 50% of HR max).
- Diabetic nephropathy – Only moderate-intensity physical exercises (walking, swimming, biking) are recommended.
- Retinopathy – Physical activities that involve an increase in blood pressure (such as weightlifting at high intensity and with Valsalva) or that involve physical contact (such as combat sports ) should be avoided. In contrast, physical activities of moderate intensity are allowed.
- Sensory-motor neuropathy and autonomic neuropathy – Regular aerobic exercise can slow the progression of peripheral neuropathy. Still, no-load exercises are recommended because of potential traumatic effects on the feet (stationary biking, rowing, swimming).
- Autonomic neuropathy – Light physical exercises aerobic activities in suitable temperature conditions, with adequate hydration are allowed.
My name is Jay Fielding. I gained an interest in fitness since I was a child, and eventually developed my passion into a career path. I am now a Certified Personal Trainer with a natural ability to program customized body recomposition and motivate people in achieving their goals, be it gaining muscle or losing fat.