A fasting value at the upper end of the range, a note about "prediabetes" in the medical report, perhaps type 2 diabetes in the family — and suddenly blood sugar becomes a topic. The good news: hardly any metabolic value responds as clearly to exercise, and your muscles play the leading role in that. Here you will learn how blood sugar regulation works, what insulin resistance means, why strength and endurance training act differently and where the line runs between training and medical treatment.
How your body regulates blood sugar
Insulin is a hormone produced by the body in the pancreas that regulates blood sugar levels. After a meal, glucose enters the blood, insulin is released and ensures that the sugar is taken up into the cells and either stored or burned there.
Glucose is stored as glycogen, in two relevant places:
- In the liver. Its glycogen store supplies the whole organism, and its main task is to keep blood sugar levels constant. After about 24 hours of fasting this reserve is used up.
- In the muscles. This store serves exclusively to supply energy to the muscle itself — it gives nothing back to the blood. That is exactly what makes it so interesting for blood sugar regulation: what the muscle takes up has disappeared from the blood.
Insulin has a second, often overlooked effect: it inhibits fat burning. If the supply of carbohydrates in the blood rises, insulin is released, hormone-sensitive lipase is slowed down and lipolysis is inhibited — at the same time insulin drives the build-up of fat stores. Anyone who keeps insulin levels up all day is permanently giving their body the signal to "store".
What insulin resistance means
In type 2 diabetes, the cells of muscle and fat tissue develop a resistance to insulin, so that the hormone can no longer take effect. The pancreas continues to produce insulin — in some cases even more — but the cells respond ever more weakly to it. Blood sugar levels rise. The training is very clear on this point: the development of resistance is favoured by excess weight and lack of exercise. Over 90 percent of all cases of diabetes are type 2, and this type is considered reversible — in contrast to type 1, in which the insulin-producing cells have been destroyed.
The course of the condition is treacherous: type 2 diabetes runs largely without symptoms, accompanied by excess weight, low physical capacity and non-specific signs such as tiredness, weakness or constant hunger. Secondary conditions — arteriosclerosis, high blood pressure, damage to nerves, eyes and wound healing — only appear at an advanced stage. An elevated fasting value is therefore no reason to panic, but a very good reason to act.
The fat distribution pattern plays a special role. What is decisive is not the BMI but where the fat sits: deposits in the abdominal cavity, surrounding the internal organs, affect energy metabolism particularly negatively and are regarded as an indicator of metabolic syndrome. Fat around the hips is less risky. What really helps against it is set out in the article Getting rid of belly fat.
Why your muscles are your biggest sugar store
Skeletal muscle is the body's largest insulin-dependent tissue — and its glycogen store is the most important customer for glucose from the blood. The logic behind it is simple: an empty store attracts sugar, a full one does not. If you move, you empty it regularly and make room for the glucose from the next meal. On top of that: more muscle mass means a bigger store. That is why strength training is not an add-on where metabolism is concerned but a main pillar — as described in the article on why strength training is essential for losing weight.
Strength training and endurance training act differently
Both forms of training improve the blood sugar situation, but by different routes. Intensive efforts such as strength training mainly empty the glycogen stores of the fast type II muscle fibres, endurance training those of the enduring type I fibres. So they clear different shelves and complement each other rather than replacing each other.
- Strength training additionally builds muscle mass and thereby increases storage capacity in the long term. The effect lasts beyond the individual session.
- Endurance training acts more directly on current expenditure and improves the heart, circulation and fat metabolism. The training highlights interval training with varying effort sequences as a particularly efficient way of increasing general physical capacity.
On the volume, the training is concrete: a normal fitness programme may and should be carried out with people with diabetes as well. The recommendation is at least 2.5 hours of moderate to vigorous endurance and strength training. Where there is additional excess weight, joint-friendly machines such as a cycle ergometer or cross trainer are the better choice at the start — the treadmill and running-intensive forms come later.
The walk after a meal
The most effective lever is often the smallest. Movement directly after a meal falls exactly into the phase in which glucose is streaming into the blood — the working muscle takes it up before the peak properly develops. Ten to twenty minutes of brisk walking after lunch or dinner is for many people the most realistic measure of all: no changing clothes, no journey, no excuse. Everyday movement does not replace training, it is a building block of its own — the background is provided by the articles 10,000 steps a day and Movement in everyday life.
The nutrition levers
On the intake side it is less about prohibitions than about the question of how fast and how high blood sugar rises. The glycaemic index measures a food's blood-sugar-raising effect compared with glucose: values above 70 count as high-glycaemic, 56 to 69 as medium, under 55 as low-glycaemic. The glycaemic load additionally takes the amount eaten into account and is therefore more usable in everyday life. From this the most important starting points follow:
- Sweetened drinks first. The sugar from them reaches the blood very quickly and leads to pronounced blood sugar peaks — with practically no satiating effect. In nutrition counselling this is the classic first lever.
- Reduce the degree of processing. The more heavily processed, the faster the rise. Whole grains, pulses and vegetables slow it down.
- Reduce carbohydrates rather than fat. The training draws on studies according to which a reduced carbohydrate share effectively counteracts insulin resistance — regardless of whether calories are reduced or not. Fat-reduced diets did not perform better. A practical framework is LOGI nutrition, which specifically avoids blood sugar and insulin peaks.
- Review sugar consumption consciously. What happens in the first few weeks without added sugar is described in the article 30 days without sugar.
Because elevated blood sugar values and cardiovascular risks are closely linked, it is worth looking at both at the same time — the article Cardiovascular disease and the right nutrition fits in here.
Where training ends and medicine begins
The primary therapy for reducing insulin resistance consists of a change in lifestyle with the aim of reducing excess weight and increasing physical capacity; drug therapy is indicated if this route does not lead to success. That does not replace a diagnosis: elevated values belong in medical hands for assessment and follow-up, and prescribed medication is never stopped on your own initiative. Anyone taking insulin or blood-sugar-lowering agents should discuss new training plans with their doctor beforehand — exercise can lower blood sugar considerably, and the medication has to fit accordingly. Coaches accompany the lifestyle, they do not treat an illness.
A related case is drug-supported weight reduction: anyone on GLP-1 therapy also loses muscle mass without accompanying training — and thus precisely the tissue that takes up blood sugar. Why strength training belongs with every weight-loss injection is therefore particularly relevant here.
Course tip from update Akademie: Blood sugar, glycaemic load, dietary patterns and the structured counselling of people with excess weight are fixed components of the Ernährungscoach programme at update Akademie — including the topic block "Nutrition and diseases" and a clear demarcation from medical therapy. Alongside your job and close to practice.
Frequently asked questions about blood sugar and insulin resistance
Is type 2 diabetes really reversible?
It is considered reversible, in contrast to type 1. What is decisive is weight reduction and increased physical capacity. How far values move back is individual and depends strongly on how long the metabolic situation has already existed — that is for the treating doctor to assess.
Does strength training or endurance training work better?
The combination. Strength training mainly empties the stores of the fast muscle fibres and increases muscle mass in the long term, endurance training those of the enduring fibres while improving the heart and circulation. The recommendation is at least 2.5 hours of moderate to vigorous training per week from both.
Do I have to give up carbohydrates completely?
No. It is about quantity, quality and distribution. Foods with a low glycaemic index, less heavily processed products and doing without sweetened drinks achieve more than a complete abstinence that hardly anyone keeps up.
Does a walk after a meal really do anything?
Yes, because it falls exactly into the phase in which glucose enters the blood. The working muscle takes up sugar and thereby dampens the peak. Ten to twenty minutes of brisk walking is already a worthwhile amount.
When should I see a doctor?
With any abnormal fasting or long-term value, with symptoms such as persistent tiredness, thirst or poorly healing wounds, and always when diabetes runs in the family. The diagnosis belongs in medical hands; training and nutrition are the accompaniment, not the substitute.
Conclusion
Insulin resistance does not develop overnight and does not disappear overnight — but it can be influenced. Excess weight and lack of exercise favour it, muscle mass and regular loading work against it. If you combine strength and endurance training, walk for a few minutes after eating and take the biggest blood sugar peaks out of your everyday life, you are working on exactly the adjusting screws that the training describes as primary therapy. A medical assessment is a mandatory part of it.
