By Unbroken | Interview with Gunnar Markusson, MSc in Nutrition. Nutrition has been part of Gunnar Markusson’s life since he first started training at 14. Today, with a master’s degree in nutrition, a bachelor’s degree in food science and 20 years of professional experience, his perspective goes far beyond what to eat before or after a workout.

For Gunnar, health is a long-term investment built around nutrition, movement, sleep, recovery and stress management. It is a philosophy shaped not only by science, but by 15 years working with people ranging from 18 to 95 years old, and by his own life as a passionate runner and cyclist.

At 50, his objective is refreshingly simple:

“I train because I want to be the oldest man in the gym, not the youngest man in the retirement home.”

We sat down with Gunnar to talk about endurance nutrition, amino acids and peptides, why he was initially skeptical of Unbroken, what changed his mind, and why muscle may be one of the most important investments we make for later life.

You’re both a nutritionist and an endurance athlete. How does that influence the way you approach nutrition?

Gunnar: I think about nutrition as something you do 365 days of the year. It isn't just the meal you have during or after exercise.

For endurance training, carbohydrates are very important. My favorite meal before exercise is oatmeal. If I’m going for a 20-kilometer run, I might have oatmeal in the morning, then during the run I’ll have carbohydrates and Unbroken. When I get home, I’ll take another Unbroken and have a good meal containing protein and carbohydrates.

I’m not really interested in short-term diets. I think in much longer periods.

At 50, I’m not training to compete at the highest level. I’m training because I want to remain healthy and active as I get older. I want to be able to run with my daughters and eventually my grandchildren.

“It’s not just what you eat during or after exercise. It’s what you do 365 days of the year.”

We hear constantly about protein. Why are amino acids and peptides so important?

Gunnar: Amino acids are fundamental to the human body. They are the building blocks of our muscles and other tissues, and they are also used throughout the body for many different biological processes.

Nine amino acids are considered essential because our bodies cannot make them and we have to obtain them through our diet. That is one reason why getting enough high-quality protein consistently is so important.

Peptides are closely connected to this. A peptide is essentially a short chain of amino acids.

And peptides are a huge topic at the moment. You hear about people using all kinds of peptides, including synthetic and injectable peptides. I look at it differently.

I’m a nutritionist. My philosophy is food first.

“There is a lot going on with peptides now. People are injecting peptides. I’m not on that boat. I think we should eat the peptides.”

What is particularly interesting about the peptides in Unbroken?

Gunnar: Unbroken contains 122 naturally occurring peptides derived from salmon. That is something I find really interesting when you look at this whole peptide revolution.

Instead of starting with a synthetic compound, you are starting with real food: salmon.

The salmon protein goes through hydrolysis, which breaks it down into free-form amino acids and very small peptides. That means much of the digestive work has already been done before you drink it.

For me, that is a very different nutritional approach.

“Unbroken has 122 peptides. When we’re talking about this peptide revolution, I think one of the best ways you can take peptides is naturally, from food.”

I know where those peptides come from. They come from salmon.

And that matters to me.

Why do you prefer natural, food-derived peptides to the synthetic peptide trend?

Gunnar: There is a lot of excitement around peptides because they are involved in processes throughout the body, including tissue growth and repair.

But that is also why I think we need to be careful.

When people talk about injecting a peptide because they want to stimulate a particular response, such as muscle growth, I think we have to remember that biological growth pathways are complicated.

You can't simply tell something you inject: go only to my muscles.

That is my concern.

“You can’t tell the peptides you’re injecting, ‘Go and make my muscles bigger.’ You can’t tell peptides where to go. They go where the body needs them.”

Gunnar is particularly cautious about unregulated synthetic peptides because mechanisms involved in growth are not necessarily exclusive to muscle tissue. As he put it during our conversation, a substance intended to stimulate growth does not inherently know that the desired target is muscle rather than another tissue, including potentially abnormal tissue.

For Gunnar, this is another reason to return to a food-first approach.

Gunnar: I love that people are thinking more about protein, amino acids and peptides and trying to improve their health. That is positive.

But there are also a lot of schemes and overstatements.

I would much rather consume naturally occurring peptides through nutrition. With Unbroken, I know the source. It comes from salmon, it has been hydrolyzed, and I can drink it.

And there is another thing that is very important to me: Informed Sport.

Every batch of Unbroken is tested through Informed Sport for substances prohibited in sport. For an athlete, that credibility is important. If you are buying some injectable peptide from somebody at the gym, do you really know what is in it?

“With Unbroken, you know where it comes from. It comes from salmon. And it’s Informed Sport tested. If you buy something from some guy at the gym, what do you really know about it?”

For Gunnar, that combination of natural origin, 122 naturally occurring salmon peptides, hydrolysis, scientific research and third-party sports testing is what separates Unbroken from many of the peptide products currently generating attention.

Why does hydrolysis matter?

Gunnar: This is what really caught my attention as a nutritionist.

Normally, when you eat protein, your digestive system has to break that protein down before its amino acids and smaller peptides become available.

With Unbroken, the salmon protein has already undergone extensive hydrolysis. You get free-form amino acids and very small peptides in a form designed to require minimal further digestion.

That is particularly interesting around exercise, when you want nutrition that is easy to consume and readily available.

“The hydrolysis process was what really caught my attention. You’re taking salmon protein and breaking it down into a form the body can readily use.”

How did you first discover Unbroken?

Gunnar: It’s actually a funny story. It was about six or seven years ago. Someone I knew through CrossFit introduced me to it.

My first reaction was basically: “Why don’t you just eat the fish?”. I was skeptical.

But he made me curious, so I started looking into it. What caught my attention was that there was science behind it. Then I started using it during my own cycling and running.

That was when it became really interesting.

I noticed a major difference in how sore my muscles felt the following day. The soreness was still there, but subjectively I felt it was around 70 to 80% less.

That was something I could actually feel in my own body.

“My first reaction was: ‘Why don’t you just eat the fish?’ Then I tried it.”

As a nutritionist, what made you take Unbroken seriously?

Gunnar: The hydrolysis process really stood out to me.

There are shelves full of supplements today, and as a nutritionist you naturally become skeptical. There are so many products making promises, often giving people something they could simply get through good food.

With Unbroken, I liked the science and the way the salmon protein is hydrolyzed. I also liked the credibility around the product.

Informed Sport testing is important to me because athletes need to know what they are taking.

There is so much noise in supplements. Credibility means a lot.

“It’s great to finally see a supplement that has good science behind it and something I could actually feel working for me.”

How do you personally use Unbroken?

Gunnar: I normally take at least two tablets per day. On heavier training days, I can take up to four.

For endurance training, I use it during exercise and afterwards. I’ve also experimented with taking it before bed.

One interesting thing I’ve noticed is my sleep data. I use an Ultrahuman Ring, and when I take Unbroken before sleep, particularly during stressful periods, I have seen improvements in my sleep score.

For me, recovery isn’t only about muscles. Sleep, stress and nutrition are all connected.

You often talk about muscle as an investment in healthy aging. Why?

Gunnar: Because maintaining muscle becomes increasingly important as we age.

We’re living longer, but the question is whether those extra years are going to be high-quality years.

Muscle mass affects your ability to remain functional and independent. Maintaining strength can help you continue walking, exercising and participating in everyday life.

That’s why I tell older people: use your muscles. Do squats. Do push-ups against a wall. Keep moving.

And it is never too late to start.

“Even if you’re 90 years old, it’s never too late to start exercising and thinking about nutrition. You can still make gains.”

I have a friend, a doctor and researcher, who has been working with patients confined to bed rest. These are people who cannot simply get up and go to the gym.

They perform a very simple exercise while lying in bed, pushing with their legs against a machine, even just a small number of repetitions each day.

His work has shown that even this type of muscle stimulation can help maintain or improve muscle mass.

I think that is a powerful example. If someone confined to a bed can benefit from using their muscles, imagine how important it is for the rest of us to keep moving throughout our lives.

So recovery nutrition isn't only relevant to serious athletes?

Gunnar: Absolutely not. Recovery is obviously important if you are running marathons, cycling long distances or training hard. But supporting muscle health and good nutrition becomes arguably even more important as we get older.

My own mother is 75. She takes two Unbroken tablets every day. She swims five days a week and walks around her hometown every day.

She is extremely active, and Unbroken is part of how she supports her muscle recovery and that active lifestyle.

That, to me, is what healthy aging should look like: staying active, continuing to use your body and giving it the nutrition it needs to recover.

“My mother is 75. She takes two Unbroken a day, swims five days a week and walks every day. She keeps moving.”

What about Unbroken for everyday wellness rather than sport?

Gunnar: For general day-to-day wellness, I like one or two tablets a day.

And there’s another habit I would like people to think about: caffeine.

People drink a lot of coffee. Instead of automatically having the fifth or sixth coffee of the day, particularly later in the afternoon, I think there are better ways to support your nutrition and energy.

Unbroken contains vitamin B12 as well as zinc and selenium, alongside the hydrolyzed salmon protein.

It isn't about getting that huge caffeine hit. It’s about supporting the body nutritionally.

If you had 30 seconds to explain what makes Unbroken different, what would you say?

Gunnar: The science, the hydrolysis process and the natural origin.

It starts with real food. It comes from salmon, with hydrolyzed salmon protein together with naturally occurring nutrients including vitamin B12, zinc and selenium.

Then you have the amino acids and peptides. That is a really important part of the story.

Unbroken gives you all nine essential amino acids together with naturally occurring low-molecular-weight salmon peptides. The hydrolysis process means the protein has already been extensively broken down into these smaller components.

And there are 122 naturally occurring peptides in that profile.

For me, that is very different from simply taking another intact protein or chasing the latest synthetic peptide trend.

“What makes Unbroken different is the hydrolysis process, the science and the fact that it starts with real food.”

What's next? The Laugavegur Ultra Marathon

Gunnar already has his next major challenge in sight: Iceland’s legendary Laugavegur Ultra Marathon in July 2027, a roughly 55-kilometer race through the Icelandic Highlands.

His target is around seven hours.

He already has some serious Unbroken inspiration. Unbroken ambassador Andrea Kolbeinsdóttir has raced the Laugavegur in just over four hours, an extraordinary time across one of Iceland’s most demanding running courses.

Gunnar isn't planning to challenge Andrea's time.

At 51, his goal is to prepare properly, complete the 55 kilometers, use Unbroken as part of his training and race nutrition, and keep proving his own philosophy that getting older doesn't mean you have to stop challenging your body.

“I’m aiming for around seven hours. I’ll be using Unbroken, and that will help me get to the goal. Stay tuned.”

A final message from Gunnar

Gunnar’s philosophy ultimately comes back to something much bigger than supplements, races or finish times.

Health is built through what we repeatedly do.

“Take care of your health. Nobody else does it for you. Use real stuff like Unbroken and eat healthy food. Life is a marathon.”

And perhaps that is the best summary of Gunnar’s approach: train, eat well, recover, sleep and keep showing up.

Because the real finish line is a long way away.

About Gunnar Markusson:
Gunnar Markusson, MSc in Nutrition, has more than 20 years of experience in nutrition and holds a bachelor’s degree in food science. He has spent 15 years working in a health-clinic environment with people across a wide age range and has additional experience as a personal trainer and CrossFit coach. He is also a lifelong endurance enthusiast, passionate runner and cyclist, and author of a book focused on the interconnected pillars of lifelong health: nutrition, exercise, sleep and stress management.