What role does sport play in the development and treatment of diabetes? Industrialization, prosperity, obesity and not least lack of exercise are responsible for the increasing prevalence of diabetes. It is usually chronic, leads to considerable damage to vessels, heart and kidneys and is therefore one of the most cost-intensive diseases of our health care system. Can sport change the course of the disease and what does a sports-loving diabetic have to know?
Type 1 diabetes and type 2 diabetes
Diabetes mellitus is a pathological disorder of sugar metabolism. We distinguish between a primary form, which is usually the result of a hereditary deficiency of the blood sugar-lowering hormone insulin (so-called insulin-dependent diabetes or type I diabetes, about 5 percent of cases), of a secondary form, in which, although enough insulin is present, this but in the sugar-using organs, especially in the musculature, can not work enough (so-called type 2 diabetes, about 95 percent of diabetics).
In both forms, there is a mostly permanent increase in blood sugar levels. The increased blood sugar leads over years to a damage of the vessels with heavy late effects for different organs.
Lack of exercise as a cause of diabetes
Especially the type 2 diabetes increases significantly in all affluent societies. It is usually associated with obesity, increased blood lipids and lack of exercise, which means that the sensitivity to the effects of insulin, especially in the muscles, decreases and therefore less sugar in the muscle can be utilized.
The vicious circle Obesity, lack of exercise and diminished insulin action often lead to significantly reduced life expectancy, despite the use of blood sugar-lowering drugs.
Sport: an important pillar of treatment
Physical activity has always been considered one of the pillars of diabetes treatment in addition to the change in diet and the use of blood glucose lowering drugs or insulin. However, experience teaches that many diabetics, especially overweight type 2 diabetics, struggle with exercise.
However, this would make it possible to achieve a decisive improvement in the sugar metabolism directed against the cause of the disease. During physical activity, there is a slight decrease in blood sugar due to increased glucose consumption, which is more pronounced in diabetics than in healthy non-diabetics.
Effects of sport on the disease process
More important than short-term blood sugar reduction, however, are the long-term effects of regular exercise on the progression of diabetes. The sensitivity of the muscle cell to insulin is increased, which means that the same amount of dietary sugar leads to a lower increase in blood sugar or the same amount of insulin to a greater reduction in blood sugar.
The response to added sugars, the so-called glucose tolerance, is improved. The metabolic performance of the muscles, ie the combustion of glucose and fats under physical stress is increased, whereby the control or the reduction of the body weight is facilitated.
Diabetics: Which sport is suitable?
Apart from very short-term stresses such as weight lifting, shot put and jumping disciplines, any form of physical activity, regardless of their duration or intensity, is basically suitable for improving the metabolic status of the diabetic. The extent and type of training are primarily dependent on age, previous sports activity, body weight and comorbidities.
Particularly suitable are types of stress that have a large metabolic effect and can be maintained for a long time, so especially endurance stress. The additional consumption of motor calories via the stimulation of the sugar metabolism (at medium intensities) is just as important here as the burning of fats at low load intensity.
Examples of types of stress suitable for diabetics:
- Inline skating
- cross-country skiing
For appropriately trained diabetics so many sports are suitable, up to many ball games or team sports.
Regular training important
But important is a regular, best daily training. Since the musculature is the target organ of the training efforts, an increase in muscle mass and strength, as can be achieved by proper strength training on resistance devices, leads to a further improvement of the mentioned drug interactions.
With existing vascular damage to the eyes and heart, however, the potential risk of excessive blood pressure increase at high power is taken into account. In these cases, high static loads such as rowing or bodybuilding, as well as intense ball sports (squash, badminton, possibly tennis) are not recommended.
Sports and insulin
Too much lowering of the blood sugar level, ie hypoglycaemia, is to be feared especially in diabetics who inject insulin. Endurance exercise is preferable in these patients because they are more controllable.
Avoid low blood sugar
For all diabetics who inject insulin or take tablets that lower their blood sugar, diet and insulin or medication must be adjusted for physical activity in order to prevent hypoglycaemia. For example, sufferers must take additional carbohydrate portions.
Since the insulin requirement is reduced under physical stress, the insulin dose must also be reduced during intensive or prolonged training. The dose reduction can be very different, but usually considerable. Closer blood glucose monitoring and the advice of a diabetes doctor are in these cases, especially at the beginning unavoidable.
In individual cases, the expected calorie requirement can be estimated and converted into calories depending on the sport and the duration of the training. In practice, however, this is rarely necessary, especially if the diabetic develops the corresponding individual experiences over time.
Why do we need sugar?
The blood sugar (glucose) is an integral part of the human blood. It is an essential nutrient for our body: many organs, especially the brain, rely on the utilization of glucose as fuel for their complex functions, which is why the blood glucose level is kept constant over a complex set of hormones in a narrow range.
If the blood sugar level increases due to the intake of food, the secretion of glucose in the cells is stimulated by the secretion of insulin from the pancreas and the surplus is stored as so-called glycogen (= storage form of glucose) in the liver and musculature. When the storage capacity of the glycogen is exceeded, it is converted into fat. If, on the other hand, the glucose level falls below a critical limit, glucose is released from the previously created liver and muscle stores.
Under normal conditions, therefore, a constant build-up and break-down of glucose takes place at approximately constant blood sugar levels. Working muscle cells consume a lot of glucose for energy; which is why a lot of glucose from your own glycogen storage and from the blood is used in muscle work. Insulin opens the muscle cell for the glucose influx.