Building muscle with PKU: Dalibor’s HIIT transformation

E.S.PKU is the largest PKU conference in Europe. Every year, Nutricia Metabolics organises events and talks to connect with PKU practitioners from all over the world. Last year, we spoke to Lal, the dancer, and Dalibor, the gymnast, about their journey to a fitter and stronger body. Read the story of Dalibor below or watch the full interview. Speak to your healthcare professional before modifying your daily exercise and diet.

Who is Dalibor?

Dalibor Dujmic is a 38-year-old PKU officer who has lived all over Europe. He started HIIT (high-intensity interval training) to lose weight and gain more control over his health.

What is HIIT?

HIIT is an intensive form of training in which short, powerful exercises are alternated with short breaks. Dalibor trains for an hour four times a week, with rest days in between. During his sessions, he burns between 800 and 1000 calories.

The advantage of HIIT is that the body cannot adapt to the routine, which keeps the exercises effective. This helps to build strength and improve fitness without stagnating progression.

Dalibor on his motivation:

"As I got older, I started thinking about my future. I want to be able to move independently at the age of seventy, without being dependent on others. Strong muscles are essential in this."

Why Dalibor started HIIT

"In addition to wanting to age healthily, I wanted to prove that PKU people can build muscle mass. I was always skinny and thought that building muscle was impossible without protein.

As I got older, I noticed that muscular men around me got more attention, while I didn't. In 2016 I moved to the Netherlands, and that got me thinking. I wanted to challenge myself and prove that it was possible.

It was not an easy road. The ups and downs were huge, especially during the COVID period, when I didn't move much and gain weight. But I kept going and found my rhythm again."

The power of exercise according to Dalibor

Improves overall health
Increase the chances of a longer and healthier life
Helps to stay independent as you age
Reduces stress and improves mental health
Reduces the risk of obesity-related diseases
Keeps muscles strong, which is crucial as you age

The Dangers of a Sedentary Lifestyle

"Did you know that the average American spends 21 hours a day sitting and is only moderately active for 3 hours? The US has one of the highest obesity rates in the world. In comparison, in Sweden, where an active lifestyle is promoted, the obesity rate is much lower."

Prolonged sitting can lead to:

Chronic diseases
Organ damage
Problems with the spine
Muscle degeneration
Circulatory disorders

Dalibor's advice: keep moving to reduce the negative effects of prolonged sitting.

Dalibor's physical transformation

His progress, measured by his clinic in Barcelona over a two-year period:

5 percent less body fat
10 percent more muscle mass
2 kilograms of extra muscle weight
More stamina, speed and strength
Less stress and a better mood
More self-confidence in social situations
Improved social contacts and more energy

But was it easy?

"Absolutely not. In the beginning it was very tough. It took me thousands of calories burned and hundreds of hours of HIIT training to get here. I feel like muscle building is slower in PKU people, but it's possible.

Over time, I noticed that I was getting stronger. I could run longer and faster and lift heavier weights. The visible results motivated me to continue."

Dalibor also discovered an unexpected advantage:

"In the gym, I met many like-minded people who are struggling with the same challenges. We support each other, which makes the process easier and more fun."

Motivation versus discipline

"What I have learned is that there is a huge difference between motivation and discipline.

Motivation is temporary and depends on external or internal factors. In the beginning it is necessary, but in the long run it does not work.

When motivation disappears, the excuses come: 'I'm too busy', 'I'm tired', or 'I don't feel like it'. At that point, discipline is crucial. Discipline means doing your training no matter how you feel.

For long-term success, you need a combination of motivation and discipline. I often didn't feel like going to the gym, but forced myself anyway. It may not have been my best training sessions, but I always felt better afterwards."

Diet and muscle building in PKU

Dalibor avoids:

Soft drinks, including diet and zero options due to aspartame
Processed snacks such as chips and cookies
Sugars and sweets
Fast food

What he does eat:

Healthy fats such as olive, coconut, and nut oils
Vegetables, with a preference for green leafy vegetables
Bananas as a source of energy
Low-protein foods such as Loprofin

"Balance is important. Being too strict can lead to binge eating. That's why I allow myself a little treat once a week. Everyone has to discover what works for them."

His nutrition strategy:

Five meals a day, including three main meals and two snacks
Protein substitutes spread throughout the day, including a serving immediately after training
A ready-to-use protein substitute for the gym for convenience

Dalibor's tip: "Use calorie and protein tracking apps to track your nutrition. The technology is there, so make use of it."