A Q&A with Aitor Viribay, Sports Performance Advisor at Calorify
Aitor Viribay brings a wealth of expertise to Calorify, blending years of hands-on experience as a pro cyclist with an academic and professional focus on metabolism and energy management. Having worked with some of the world's top endurance athletes, including at INEOS Grenadiers Cycling and Salomon, Aitor is a leading voice in human performance. Now joining Calorify as a Sports Performance Advisor, he shares his insights on energy expenditure, the science behind endurance sports, and his vision for the future of performance measurement.
Q: You seem to have a lifelong history with metabolism, from having been a pro cyclist yourself, to working with some of the best endurance athletes in the world. What inspired this passion and how has it influenced your academic and professional career?
A: Being an athlete myself helped massively, but I would say it has been something natural to me around human performance first, and then understanding how to reach that peak performance. When I was 16 I already read a lot about physiology (I probably couldn't understand what it was in front of my eyes), and that predisposed me to dig deeper in my studies and had an influence on my interests. So probably I am the professional I am partly because of that influence of being a young elite athlete myself and that relentless curiosity to learn that has always inspired me.
Q: Most recently you were with INEOS Grenadiers Cycling. What were some of the projects you did with them, and what was it like working with athletes on the ground?
A: Cycling has always been my little world, so I can say living the experience of being on the most professional cycling team of the last 20 years has been a real privilege. As part of my role as Head of Human Science, I have carried out many interesting projects related to human performance and management of nutrition, supplementation or even load monitoring. Probably one of the most challenging and fulfilling one has been the research about their energy expenditure. In the current cycling era, energy is becoming very precious, so you can imagine how important it is to properly understand energetic demands and how to manage athletes' energy to get them where they need to be. All this has involved many metabolic testing and also a good amount of DWL tests that has helped us create equations and a pretty good understanding of our “metabolic machines”.
Working with the best metabolisms in the world is fantastic because nothing is set in stone about them. Unfortunately, science doesn’t generally consider these populations, so our knowledge about them is limited. It’s like working with F1 cars, you will only access that knowledge if you work with/for them, because it won’t be published or accessible anywhere publicly. Testing some of the best metabolisms in the world means learning every day, rethinking knowledge as you think you understand it and creating new hypotheses that can solve their performance equations. It’s truly like an artisan's work and I have always loved it.
Q: You have previously stated that energy budget is the single most important measurement for endurance athletes. Why is that?
A: Speed or power is essentially energy. There is no speed without power, and there is no power without calories, without energy. Everything we study around performance, as physiological adaptations and metabolic outcomes, are essentially their capacity to produce energy in the right way. If you can develop more energy and you’re trained to convert that energy into the pedals or into the foot stroke, you’ll bike or run faster and longer. Put simply, the energy budget determines how an endurance athlete can train, adapt and perform over the days, weeks, months and even years! The best athletes in the world are the best humans producing energy and using it in the right way.
Q: You’ve worked with Kilian Jornet on his energy expenditure along with numerous other top athletes in the endurance space. What is it like working with these athletes, and what lessons are being learned from measuring total energy expenditure?
A: Working with these athletes is a privilege and a huge challenge at the same time. Just imagine having access to a very unique and exceptional piece of art. You need to understand how to manage it, how to manipulate and learn from it, but mainly you need to make sure you don’t screw it up. You need to invest a lot in learning from these pieces of art that high level athletes represent. The main lesson we are learning is how good they are using energy. While a normal sedentary person can burn 2000 kcal per day, these athletes can burn up to 9000 kcal per day in very extreme situations. That’s a huge amount of energy and it has several implications that need to be considered. With Kilian for example, we learned how much energy can be sustained during one of the most extreme endurance events (more than 20 days moving around 15h per day average in the mountains - altitude included - completing all 82 peaks above 4000m in the Alps). When you move that much and it's sustained in the time, if you don’t show a massive capacity to expend energy, you simply reach a moment when you cannot move anymore, you run out of energy, or simply your metabolism gets fatigued and starts to “save energy”. Kilian showed a huge capacity to expend energy sustained over the days, something that is very very unique. As he revealed publicly, 8300 kcal/day average. This knowledge is very unique and gives us examples of the peak human capacities.
Q: Recently, you’ve made the switch to work with Salomon. Can you tell us more about that transition and what you’re looking forward to with this new group of athletes?
A: I know this huge opportunity comes with great responsibility and honor. The challenge is big but we will have some fun. Salomon wants to give more support to athletes, help them with their performance, environment support and scientific research. We want to set a structure where we can help athletes learn about themselves, bring science and at the moment-unavailable knowledge around trail running and its demands. The goal is to set a culture based on scientific approach where we can test, learn, inform practices and create new hypotheses through a cutting edge scientific approach. And of course, one of the first topics we need to understand is the energy relationship between athletes and their efforts. It will be so fun!
Q: Why did you join Calorify?
A: The question is really why didn’t I join earlier? Ha ha.
Calorify solves a real problem, which is the measurement of energy with one of the most accurate and valid technologies. This is a very complex, expensive and hard to execute measurement, and Calorify is democratizing it to make it available for everybody. One of the main disruptions we are seeing nowadays is that the energy requirements calculations we do and the idea of how much energy we are expending is not aligned with what we are really measuring. We are assuming a normal person needs 2000kcal per day, but then we are measuring a completely different number, meaning there is still a lot of work to be done to really help people become more healthy and perform better. Calorify will unlock this very soon. This is already impacting massively in endurance sport performance, like it has done in my previous team, through informing internal fatigue management, training and nutrition interventions, and most importantly looking into another dimension that has never been part of the equation until now.
Athletes, coaches and teams will use DWL to inform their practices and as a marker of performance and training sustainability. Same as we are using HR, HRV, lactate, or blood test routinely, DWL will be part of the equation very soon, but with a wider perspective as its scope is much more complete than other isolated markers. In my humble opinion, DWL routine testing will cover big gaps we currently have in the sports and health areas.
