Physiology, Podcast, Training

Applied triathlon science with Olav Aleksander Bu (Norwegian Triathlon Olympic team) | EP#264

 December 14, 2020

By  Mikael Eriksson


Olav Aleksander Bu is a sports scientist and elite coach working with the Norwegian Triathlon Olympic team. He is heavily involved in testing, performance optimisation, and the scientific approach adopted by the Norwegian Olympic Team, that has brought so much success in races from Super League through World Triathlon Series and Ironman 70.3 for athletes like Kristian Blummenfelt and Gustav Iden.

In this Episode you'll learn about:

  • Olav's role and responsibilities with the Norwegian Triathlon Olympic team
  • Changes implemented in the team's training and methods over the course of Olav's work with them
  • Testing methodologies
  • Considerations of training at various intensities: from low to high intensities
  • How to achieve very high training loads
  • The impact of athlete phenotype on training planning
  • Gadgets and technology

Sponsored by:

Precision Hydration

Precision Hydration
One size doesn't fit all when it comes to hydration. Take PH's free Triathlon Sweat Test to get personalised hydration advice tailored to what you're training for. Use the promo code THATTRIATHLONSHOW15 to get your first box for free!

The finest triathlon wetsuits, apparel, equipment, and eyewear on the planet. Trusted by Lucy Charles, Javier Gómez-Noya, Flora Duffy, Mario Mola, and others. Visit for 20% off your order.



04:50 -

  • I have all the way since I was child always been very into sports of all kind, and as an adult I was involved in sailing for many years.

    My first encounter with triathlon was the Norseman Extreme Triathlon, where the competitors passed by the farm where I grew up every year.
  • The first part of my work life was as an engineer (I have a degree in civil engineering), and I started and developed several companies within the tech business.

    Later on as an adult, I started to get fascinated by triathlon and got involved in the sport myself as well.

    Especially the cycling discipline appealed to me, much because of the great amount of data that could be withdrawn from power, speed etc.

    Unfortunately, however, I became injured, which stopped me from developing my own cycling ability.

    But at this point I had gotten really into sports science and the physiology behind performance and decided to start studying physiology (this was in 2012).

    As I had finished my studies, I was keen on working with triathlon and triathletes and worked my way towards getting a role within the Norwegian Olympic Triathlon Team.

    At the moment, 40-50 % of my work is for the Norwegian Olympic Triathlon Team, and the rest of the time I am doing physiology consulting missions for a broad variety of other sports.

A typical work day (when working with the Triathlon Team)

09:35 -

  • This depends a little bit on wether the team is training at home in Norway or if they are away on camp abroad.

    When they are training on home soil, I work very closely with the head coach of the team Arild Tveiten, reviewing, analyzing and planning the training of the athletes, all on a very individual level.

    Another very big part of my work is to analyze and plan physiological performance tests that the athletes conduct on a regular basis.

    When they are away on camp, I am mostly analyzing the athletes’ responses to certain specific stimuli like altitude or heat adaption.

    Leading into the Tokyo Olympics, optimizing heat adaption has played a big part of my work.
  • My work with the team has also changed over the years, first (in 2016 when I started working with the team) I had more of a passive role, merely collecting data from the athletes and doing analyses.

    After 2016 and the Rio Olympics, we started to implement some of the conclusions that could be withdrawn from the data that I had been collecting and analyzed.
  • One of the most important elements that we incorporated from these initial analyses is intensity control.

    We strive to try and understand exactly what happens (metabolically and physiologically) at different intensities (energy outputs), not only in a fresh state but in fatigue states as well.

    By understanding these processes better, we are convinced that we can ”break down” the races in several parts and target the demands of each part separately in the training, hence increase performance.

    Since a triathlon race is so extremely complex, we believe that being able to break down each key element to single parts is crucial to achieve success.
  • I have also helped the team to develop some technical aspects related to triathlon and racing, primarily by upgrading things on the bikes, such as the bike fit.

    Examples on technical aids that we use within the team are the Stryd running power meter, smart swim paddles and physiological test measurement devices.

Physiological testing

34:30 -

  • The tests that we conduct vary slightly depending on what time of the season it is, however, they include metabolic testing, force/velocity plotting, power duration curve, influence of fatigue, blood biomarkers and a few more.
  • We use metabolic testing, like determining VO2max and VlaMax, and implement these parameters into a broader sense, which basically means relating these parameters into what kind of capacity (performance) the athlete has.

    One can say that VO2max and VlaMax gives you a 2 dimensional picture, and you need to have the 3 dimensional perspective in order to bring out a great race performance.

Cross-over effects between disciplines

51:10 -

  • We definitely see plenty of cross-over effects between the disciplines, VO2max is for instance very similar for cycling compared to running, but differs slightly for swimming.
  • We have been very focused on developing the VO2max of our athletes during many years now and of course, this is a very important parameter, but lately we have slightly shifted our focus to performance, as, after all, this is our primary outcome measurement.
  • I try and determine what physiological ”domain” the athletes are closest to during race, and in turn, this part of their physiology is what we are trying to develop the most.

    For instance, in Olympic distance triathlon races, the elites are racing very close to their anaerobic threshold, and consequently, this physiological parameter (anaerobic threshold) would be the most important to focus on.

    When it comes to developing anaerobic threshold, the strategy I would primarily use is to try and extend the time an athlete can stay on his or hers anaerobic threshold rather than increase the power for shorter durations.

    If we instead would take Ironman racing, then you’re racing quite far from the anaerobic threshold, and hence you should instead mainly been focusing on the race specific intensity.
  • When it comes to the low intensity sessions, the purpose of these sessions are to support the development of the race specific paces or powers (or the duration of the same).

    I look at the race specific workouts (anaerobic threshold workouts in Olympic distance triathletes), as the key workouts and also a great indicator of progress.

    It is therefore crucial to not let the low intensity workouts hamper the execution of these key workouts, and this is what should control the intensity of them (making sure that you’re not fatigued going into the these sessions).
  • Even though we do plenty of measurements in order to objectively quantify intensity and other areas, I value subjective impressions from the athletes (how they feel) extremely much.

    When I do tests, I always relate the measurements to how the athletes feel and if their feelings deviate form what the data says, this is always something you need to try and figure out why.

    This also comes into play when they do easy/low intensity sessions, for the vast majority of the time, they just go by feel (easy effort), which almost always corresponds really well to the data (the athletes are extremely ”well-tuned” into different efforts). 

Training load

1:2025 -

  • Also when it comes to training load, we mainly go by how the athletes feel, this is the by far most important factor to consider.

    In addition this, we also look at HRV, resting HR and total energy expenditure, but only as secondary measurements.
  • As many of you already know, the Norwegian triathlon team train very high volume, maybe the most volume compared to other nations and/or training groups.

    However, I would also like to state that it probably doesn’t differ too much from what some of the other highly successful train in terms of volume.

    But we are probably close to the very limit of how much training volume one can have without starting to see a decline.

Training intensity distribution

1:25:30 -

  • The training intensity distribution varies quite a bit, both from year to year as we are experimenting with different types of training, and also during different phases of the year.

    I don’t really know what it would be on average, and frankly I don’t pay much attention to that either.
  • In terms of polarized training, I would say that we are not fully adapting this concept because in triathlon, the ”power output”/intensity is much more stable compared to cross-country skiing, which is where the polarized training concept originated, and because of this we tend to keep the intensity during the intervals somewhat lower and the duration slightly longer instead.

Rapid fire questions

1:29:35 -

  • What is your favorite book, blog or resource related to endurance sport? No specific resource, it depends on what I am working on, but as I try and learn something new or try and understand something, I am always trying to challenge my own views by looking at plenty of different kinds of materials.
  • What is your favorite piece of gear or equipment? I can’t tell you until after the Olympics…
  • What is a personal habit that has helped you achieve success? I always try and surround myself around really smart and good people!


Mikael Eriksson

I am a full-time triathlon coach, founder of Scientific Triathlon, and host of the top-rated podcast That Triathlon Show. I am from Finland but live in Lisbon, Portugal.

Please contact me if you have feedback on the podcast or want to make suggestions for improvement or send in a question for a Q&A episode.

If you are a long-time listener and appreciate the value the podcast brings, please consider taking a couple of minutes for leaving a rating and review on iTunes/Apple Podcasts, or wherever else you can think of leaving a rating and review.

  • It’s great to have guests that work with elite athletes, but it’s also very disappointing to get
    extremely vague and generic answers. Example: 10 thousand hours of SmO2 (NIRS)
    data, but an evasive non-answer about how it’s actually used.

    It’s interesting to hear that he believes most elite athletes have a central limitation.
    A week earlier, San Millan said just the opposite.

  • {"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

    Explore our products and services