Health improvement through physical exercise in patients with diabetes

Diabetes is a chronic disease that affects millions of people worldwide. Effective management of diabetes requires a multifaceted approach, including significant lifestyle changes. Physical exercise plays a crucial role in this management, offering proven benefits in regulating glucose, improving insulin sensitivity, and strengthening the patient’s overall well-being. This article explores the relationship between physical exercise and improved health in patients with diabetes, drawing on the latest evidence and providing practical recommendations for health professionals.

Diabetes mellitus, especially type 2 diabetes, has become a global epidemic. According to the World Health Organization, more than 422 million people suffer from diabetes worldwide. Physical exercise is recognized as a cornerstone in the treatment of diabetes, not only for its impact on weight control and cardiovascular improvement, but also for its direct effect on glycemic control.

The scientific literature provides robust evidence on the benefits of exercise in patients with diabetes. A recent meta-analysis (Smith et al., 2021) demonstrated that both aerobic and resistance exercise improve glycemic control in patients with type 2 diabetes, with a significant reduction in hemoglobin A1c (HbA1c).

Aerobic Exercise: Includes activities such as walking, swimming or bicycling. The American Diabetes Association recommends at least 150 minutes per week of moderate-intensity aerobic activity, or 75 minutes of vigorous intensity. In addition, through telerehabilitation platforms such as TRAK, patients can access personalized aerobic exercise programs from the comfort of their homes, which can improve their adherence to treatment and make it easier to track their progress.

Resistance Exercise: Weight lifting or resistance band exercises. It is suggested to incorporate these exercises at least twice a week, complementing aerobic exercise. TRAK offers resistance exercise options tailored to the individual needs of patients with diabetes, allowing them to strengthen their musculature and improve their functional capacity, all under the supervision of healthcare professionals.

Flexibility and Balance Training: Particularly important for older adults, helping to prevent falls and improve mobility. Through TRAK, patients can access flexibility and balance training programs designed specifically for their needs, helping to maintain their long-term independence and quality of life.

• Improved Glycemic Control: Exercise increases glucose uptake by muscles, which may reduce the need for medication.

• Reduced Cardiovascular Risk: Diabetes increases the risk of cardiovascular disease. Regular exercise helps reduce this risk.

• Weight Loss: Being overweight is a significant risk factor for developing type 2 diabetes; exercise helps control weight effectively.

• Improved Mental Health: Physical activity improves mental health, reducing symptoms of depression and anxiety, which are more common in diabetic patients.

Exercise plays a major role in most diabetes treatment protocols. In addition to the physiological adaptations induced by exercise common to all people, such as the reduction of cardiovascular risk factors or the improvement of self-esteem, we will highlight others, specific to patients with diabetes mellitus.

Diabetes Mellitus type 2

With respect to the effect of regular exercise on these patients, there are apparently contradictory results, produced mainly by the differences between the intensity, frequency or duration of the training sessions; the duration and severity of the disease; and the time elapsed between the training session and the assessment of glucose tolerance. Thus, for example, if the test is performed 48 hours after the last exercise session, the effect is much smaller.

In general, endurance training is considered to improve insulin sensitivity, although this is not always associated with improved glycemic control. Among other effects, exercise contributes to the control of body weight and the reduction of fat weight, which has been related to an increase in insulin sensitivity, allowing, in many cases, a reduction in the dose of insulin or oral antidiabetic drugs.

On the other hand, regular physical activity reduces the development of type 2 diabetes in subjects with impaired glucose tolerance, in patients who have suffered gestational diabetes or in those with a family history of type 2 diabetes mellitus. The increase in muscle capillary density, the potentiation of the oxidative capacity of skeletal muscle or other adaptations to training such as the increase in muscle cell GLUT4 transmembrane transporters, are adaptations related to the preventive character of regular physical activity.

Despite the insulin-induced increase in glucose consumption that can last up to 5 to 7 days after exercise in trained subjects, patients with type 2 diabetes may not improve fasting blood glucose. Glycosylated hemoglobin (HbA1c) indirectly indicates the average blood glucose over the last couple of months, since the degree of glucose binding to hemoglobin is proportional to the average plasma glucose concentration, and is a useful way of assessing the degree of control of diabetic patients.

Since moderate-intensity aerobic exercise reduces glucose levels in hyperglycemic patients with type 2 diabetes, and insulin sensitivity remains increased for several hours after the training session, it seems reasonable to think that a program that includes 4 to 7 weekly sessions could reduce blood glucose and glycosylated hemoglobin levels, without a significant effect on fasting blood glucose or glucose response to meals. Therefore, regular physical activity could improve long-term glycemic control in these patients.

Type 1 Diabetes Mellitus

In order to benefit from common exercise adaptations, and although unlike type 2 diabetes, exercise is not considered part of the treatment of type 1 diabetes, physical activity should be recommended for these patients, as long as blood glucose can be well controlled (< 250 mg-dl-1 and absence of ketosis). There are sufficient data to ensure that more active subjects enjoy a higher quality of life.

Although it appears that exercise does not accelerate retinopathy or diabetic nephropathy, it is considered wise to avoid high-intensity exercise that could excessively increase blood pressure or produce head contusions, especially in cases of proliferative retinopathy.

Exercise is considered one of the pillars of the treatment of type 2 diabetes mellitus, as it improves insulin resistance. In the case of type 1 diabetes, although it cannot be considered as a treatment method in itself, since these patients generally require insulin, it is of great importance when it comes to improving lifestyle, and above all in the prevention of some of the complications. It is of great importance to consider the possible complications of diabetes when establishing the exercise prescription protocol, especially retinal disorders.

Diabetes Mellitus type 2

As a general idea, the core of the programming will consist of aerobic exercises, involving large muscle groups, for about 30 minutes, at around 60 – 70 % of the subject’s maximum heart rate. However, the determination of this variable can be complicated, especially if the patient suffers from vegetative neuropathy, or is under treatment with certain drugs, such as beta-blockers. Patients without diabetic retinopathy can tolerate strength exercises or higher intensities of aerobic exercise.

Training sessions should begin with a warm-up, with low-intensity aerobic exercise and stretching, lasting 5 to 10 minutes, to reduce the risk of injury. Then start with the moderate to high intensity session, lasting half an hour or more, depending on the patient’s tolerance. It is advisable to monitor the heart rate with a heart rate monitor in order to ensure the appropriate intensity. Each session should conclude with a 5 to 10 minute cool down phase to avoid the risk of cardiovascular complications such as post-exercise hypotension, silent angina, etc. Stretching exercises, walking or other rhythmic activities are again useful in this phase. These sessions would be devoted to aerobic activities or muscle strength sessions.

In order to improve insulin sensitivity, control blood glucose levels, and contribute to weight control and overall fitness, the sessions should be repeated at least three times a week.

Although blood glucose regulation in these patients is different from that of healthy people, high blood glucose levels usually normalize with moderate-intensity exercise.

Diabetes Mellitus type 1

Exercise should be started between 1 and 3 hours after food intake, when blood glucose is above 100 mg-dl-1.

If the exercise is prolonged and of high intensity, carbohydrates in the form of bars or similar should be administered during exercise and some extra food at the end, in order to avoid post-exercise hypoglycemia.

If the exercise is intermittent, of high intensity and short duration, the risk of hyperglycemia increases markedly, and small post-exercise insulin supplements may be necessary.

There is no exact rule for establishing the amount of carbohydrates that should be consumed in prolonged exercise to avoid hypoglycemia, although it can be approximated by considering intensity and duration. In most cases, about 20 g of carbohydrates can be consumed every half hour of exercise to keep blood glucose within normal limits; however, this should be accurately assessed by making systematic determinations during exercise.

In agreement with the physician, the insulin dose and administration schedule can sometimes be modified in order to avoid hypoglycemia. For example, patients taking a single dose of intermediate-acting insulin (neutral protamine Hagendor: NPH) can reduce the dose by 30-35% in the morning before exercise. They could also split the dose in two: 2/3 in the morning and 1/3 in the afternoon or evening, before snack or dinner, if post-exercise supplementation is needed. When using combinations of short-acting and intermediate-acting insulins, they can decrease the dose of the short-acting insulin by 50%, or even suppress it before exercise. They can also decrease the intermediate-acting insulin before exercise and administer a rapid-acting dose after exercise, if necessary. Patients using several doses of rapid-acting insulin can reduce the pre-exercise dose by 30-50%, and adjust the post-exercise administration according to blood glucose results and personal experience with hypoglycemia. All these adjustments should be made on the advice of the physician and with accurate assessment of blood glucose levels.

Telerehabilitation platforms, such as TRAK, are valuable tools to facilitate adherence to exercise programs in patients with diabetes. These platforms offer personalized strength and aerobic exercise prescriptions, designed by physical therapists and tailored to the patient’s weekly progression. Strength exercise, critical in diabetes management, requires precise weight progression to nurture the desired muscle growth. TRAK allows patients access to a variety of exercises, from squats and lunges to specific movements for gait and upper limb strength, including abdominal and core work, crucial for reducing abdominal fat, a significant concern in this condition.

In addition, TRAK includes stretching and joint mobility exercises, essential to prevent pathologies associated with diabetes, such as diabetic foot, and promote mobility, decreasing neurological symptomatology. Accompanying these strength routines, aerobic work complements the exercise regimen, and TRAK’s ability to pace exercise progressively allows physical therapists to monitor and adjust training on a day-to-day basis, accurately and carefully navigating the fluctuations inherent to the pathology. Together, these platforms contribute significantly to improving the quality of life of patients with diabetes, facilitating a comprehensive and personalized approach to disease management.

Physical exercise is an essential component in the management of diabetes, offering significant benefits in glycemic control, cardiovascular risk reduction and improved quality of life. It is crucial that healthcare professionals promote an active approach to exercise in patients with diabetes, taking advantage of tools such as telerehabilitation platforms to maximize outcomes.

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