This furtive but constant look into his sports bag gave rise to rumors: Is Alexander Zverev illegally given tactical information when changing sides during his matches via social media? Or why does the best German tennis pro keep casually looking into his tennis bag? “He then always checks his blood sugar level. I’m sitting right next to it and can see it clearly,” Davis Cup coach Michael Kohlmann told DW.
Zverev has had diabetes I since childhood, and he was diagnosed with this disease at the age of three. The 25-year-old explained this this summer. At that time, the doctors told him that he could not become a top athlete with type I diabetes. “I think I can say today that they were wrong,” emphasized Zverev. He personally has no problems doing sports at a high level because he always has everything he needs with him and now knows his body very well.
What happens to those affected?
In type 1 diabetes (diabetes mellitus), the body cannot produce insulin. It is an incurable disease. Without the insulin produced in the pancreas, the food consumed cannot be properly utilized. The absorbed sugar accumulates because it cannot be transported into the body cells. A high concentration of sugar causes a number of ailments. This can lead to disorders of consciousness, the affected person can even lose consciousness completely (diabetic coma). Patients with type 1 diabetes therefore have to inject insulin every day.
However, most people suffer from type 2 diabetes. This is a chronic metabolic disease in which the body develops insulin resistance over time. In contrast to type 1, high blood sugar levels in type 2 can be lowered with a healthy diet and plenty of exercise.
Sport and diabetes, can that work?
“You can achieve an incredibly high level of performance with this disease,” says Christine Joisten from the Institute for Movement and Neuroscience at the Sports University in Cologne, referring to both types of diabetes. “We have an incredible health benefit behind the movement. And that across the board, including positive psychological effects such as increased self-esteem,” says the scientist. Medicine has a pretty good handle on this disease.
Type I diabetics – like Alexander Zverev – have to inject insulin their whole lives
But: In order to be able to develop their full potential – and this applies to both competitive and amateur athletes – it is important for every athlete to get to know their own body well. Exercise empties the sugar stores in the muscles and liver, and the body has to replenish them after exercise. “But injected insulin doesn’t adapt to the body,” says Joisten. It is therefore necessary to take a very close look at how each individual reacts to the respective stresses.
After all, maintaining a normal blood sugar level is always a major challenge during training, competitions and travelling. Medical advances have now made it possible to change the insulin to be administered and the supply of nutrients within minutes in order to achieve an optimal level at best achieve blood sugar control. Therefore, a doctor should be consulted in any case, who will support the adjustment in the short and long term.
Which sports can be practiced?
“You can actually do all kinds of sports,” says Joisten. It doesn’t depend on a special endurance or an increased occurrence of strength. Above all, regular exercise is crucial for a positive influence. However, there are also sports that involve an additional risk, also because they can endanger others. For example when diving or climbing. “If the person affected has hypoglycaemia and is no longer in control of their senses, this can lead to problems for everyone involved,” emphasizes Joisten.
Diabetics of any type must check their blood sugar levels regularly
Athletes would have to prepare even more carefully for the practice of such sports, which are risky for diabetics, than they already do with this disease. The insulin dose and carbohydrate intake would have to be meticulously adjusted to such activities. Of course, you should also consult a doctor. “The type of sport itself doesn’t matter. The type of execution determines the success,” says Joisten.
Good preparation necessary
In the case of Alexander Zverev, preparing for a match requires a few minor changes compared to the usual Davis Cup team process. “Of course, we’ve known about the problem for a long time. That’s why we try to tell him our training times early on and, if possible, to have the training take place the day before at the same time as the match. Then Alexander can adjust his diet and everything else to it.” , coach Kohlmann explains to DW. However, the adjustments are only minor. “As a professional athlete, he has it under control. And he has a lot of experience with it and knows exactly how to adapt to the respective situation.”
What mistakes shouldn’t be made when exercising with type 1 diabetes?
“Ignoring the disease,” says Joisten. “You have to use sport wisely. Sport should be seen as part of the treatment concept but also as part of the life concept.” The athletes would have to take a closer look at how they deal with their conditions. Above all, the risks associated with the disease should not be downplayed. It is also not important when the diagnosis is made. In the vast majority of cases, type 1 is already diagnosed in childhood and adolescence – as was the case with Alexander Zverev.