Life with Diabetes — The Story of an Endurance Athlete

Diabetes is not uncommon among athletes, yet we don't talk about it enough. It is surrounded by a stigma, causing those affected to prefer staying in the background and avoiding public exposure.

Žiga Papež is different. He has been living with type 1 diabetes since he was 12 and in recent years, he has been raising awareness about it. He wants to prove that it is possible to live a normal life with diabetes, including taking on challenging endurance endeavors. This is why he set out and successfully completed the endurance challenge North Cape 4000.

In this blog, he helps us uncover the details of living with diabetes, what adjustments are necessary, and how to approach athletic challenges.

The Art of Controlling Blood Sugar in Every Situation

Diabetes is not something that limits you only occasionally. It requires constant monitoring — at home, at work, and during physical activities.

"People imagine that blood sugar levels change once or twice a day, but in reality, these changes happen very quickly," Žiga explains at the beginning of our conversation, clarifying that fluctuations in either direction — high or low — can be dangerous.

Regulating blood sugar is an art in itself. Unfortunately, there is no golden rule that all diabetics can follow to control their condition. There are guidelines, but it is up to each individual to find what works for them and under what conditions their body responds best.

"I kept a journal for a long time, tracked my body's reactions, and recorded everything. That’s how I learned how my body behaves under different types of exertion, and based on that, I adjusted both my training and diet," Žiga shares his approach to managing the disease.

Type 1 diabetes is an incurable autoimmune disease that requires insulin treatment due to the non-functioning of the pancreas. It is less common than type 2 diabetes, affecting around 10% of diabetics, and primarily occurs in children and adolescents.

It's hard for an average person to imagine the fluctuations in blood sugar levels and how little it takes for these to “jump” to one side or the other. The range within which diabetics can maintain their blood sugar levels is narrow, while spikes after food intake can be quite significant.

What does this mean in numbers?

Blood sugar levels are measured in mmol/L. Target ranges vary depending on factors such as meals, physical activity and the individual's treatment plan.

Physical activity can significantly affect blood sugar levels. During prolonged endurance exercise, levels may fall, increasing the risk of hypoglycaemia.

Let’s put the numbers in context. For Žiga, even a relatively small amount of carbohydrates can noticeably affect his blood sugar levels. For example, he has observed that half of a 4Energy Bar, containing 15 grams of carbohydrates, can raise his blood sugar by around 1 mmol/L. The timing and extent of this response can vary depending on factors such as exercise intensity.

As a result, diabetics constantly have devices with them to measure their blood sugar levels. Žiga also continuously uses an insulin pump, and during cycling, he has a phone mounted on his handlebars, which receives data every 5 minutes from a glucose monitor on his arm, providing him with real-time blood sugar readings.

"During physical activity, I have to monitor my blood sugar levels. I constantly track the amount of sugar in my blood via the monitor. It changes depending on the intensity of the activity and the energy reserves I’ve built up beforehand through nutrition. Even the food I ate 48 hours ago plays a role," he explains.

Everyday Nutritional Adjustments of Diabetics

For a person with type 1 diabetes to manage their condition effectively, diet and carbohydrate intake need to be considered alongside insulin treatment and physical activity.

As a result, diets like LCHF (low-carb, high-fat) and keto are quite popular among diabetics since both limit the intake of carbohydrates, which have the most aggressive impact on blood sugar spikes.

However, Žiga, who follows a slightly modified version of the LCHF diet, emphasizes that what works for one person might not work for another. Individualization is key, and there’s a lot of trial and error involved in finding what suits you best.

"In the context of diabetes, the focus is on the LCHF diet, meaning 'low-carb, high fat.' I personally advocate for including more protein while definitely reducing carbohydrates. There are many approaches. We’ve learned that our bodies function differently. In the end, each person has to figure out what works for them and which diet makes them feel best."

Carbohydrates are still present in Žiga's diet, particularly around the time of exercise, when they can help support glycogen stores. Physical activity can significantly affect blood glucose levels, so Žiga adjusts his carbohydrate intake based on his glucose readings and the demands of the session.

"When I’m not burning calories, I consume as few carbohydrates as possible. It's different around workouts — then they’re back on the menu. Otherwise, I try to avoid them or drastically limit their intake in everyday life. As a result, I increase my intake of protein and fats. This helps prevent sudden sugar spikes."

It’s precisely these sugar spikes and the resulting sudden drops that diabetics strive to avoid by regulating their diet. Large fluctuations can throw the body into an abnormal rhythm, leading to unwanted side effects, especially extreme energy swings.

"I constantly try to prevent sugar crashes because when they happen, I fall into a strange rhythm where my blood sugar drops, and I then have to overcompensate. This causes my blood sugar to rise quickly and then drop rapidly again. This is the worst-case scenario for diabetics, and even for a healthy person. It feels like you're constantly in a cycle of being in a good mood, then depressed, back in a good mood, and then depressed again."

The Impact of Diabetes on Athletes

For athletes with type 1 diabetes, nutrition during exercise often requires additional planning. While sports nutrition commonly focuses on carbohydrates, the amount and timing may need to be adjusted according to factors such as exercise intensity, insulin and blood glucose levels.

The adjustment comes in the form of smaller but more consistent carbohydrate intake, aligned with data from the athlete’s glucose monitor.

"I add very little carbohydrates, but I add them constantly. For example, 10 grams every 15 to 20 minutes. Of course, it depends on blood sugar levels," explains Žiga, who prefers carbohydrates in liquid form, as it allows him the most precise dosing.

"I usually have water in one bottle and 60 grams of carbohydrates in the other. We're talking about a drink with sugar and electrolytes," says the 31-year-old, who primarily relies on Nrgy Drink 90. "I drink it gradually, depending on the activity. If my blood sugar is high, it means I already have enough sugar in my body, and I don't need to take more. In that case, I drink only water. When the sugar levels are low, I start drinking the isotonic drink."

One of the key products for energy intake during exercise for healthy athletes are energy gels. For Žiga, however, energy gels are primarily a backup, as the amount of carbohydrates they provide at once can be difficult for him to manage during exercise.

"I know athletes often consume 30 or 45 grams of carbohydrates at once. I can't afford that because my sugar levels spike too much, which leads to issues like cramps, water retention, and overall poor feeling."

"I use gels only when my blood sugar starts to drop dramatically, and I need a quick energy source. For example, before climbs, I add 20, sometimes up to 25 grams of carbohydrates. If I didn’t add any, my sugar levels would drop by 2 to 3, sometimes even 4 units."

Gradually adding carbohydrates is key to successfully completing a physical activity. Any mistake or moment of carelessness, as Žiga calls them, can lead to problems. While these aren't critical at first, they can bring frustration, as they indicate that a mistake has been made.

He explains that symptoms of high blood sugar can vary considerably between individuals and may become more noticeable as glucose levels rise. These can include increased thirst, fatigue and blurred vision.

Despite all the adjustments diabetes demands in combination with sports, Žiga is convinced that physical activity is beneficial for diabetics: "Sports are good for diabetics, but extreme sports not so much. Aerobic activities are great for sugar control, as they lower blood sugar levels and help regulate it better. You also end up using less insulin," he concludes.

Conclusion

Diabetes requires numerous adjustments, both in everyday life and in sports. Constant monitoring of blood sugar levels demands discipline from individuals, as they must always carry the necessary medical devices with them.

Blood sugar levels fluctuate continuously, and target ranges vary depending on factors such as meals, physical activity and an individual's treatment plan. During exercise, glucose responses can also vary depending on the type and intensity of activity.

People with type 1 diabetes may need to adapt their nutrition around exercise. Carbohydrate intake and timing should be individualised according to factors such as insulin, exercise intensity and blood glucose levels. For Žiga, this means consuming carbohydrates in smaller, regular amounts and adjusting them according to his glucose readings.

Nevertheless, physical activity is generally recommended for people with diabetes and provides numerous health benefits. In people with type 1 diabetes, its effects on blood glucose and insulin requirements vary, so exercise, nutrition and insulin adjustments need to be individualised.