Sebastian Weber reently gave 2-day workshop in Munich about Energy metabolism diagnostics – and how to apply it in training. In attendance were national ski coaches looking to expanding their knowledge. The event was organized by INSCYD partner, the German Ski Association.

Do you want to have an inside look at what the national coaches learned? Or are you interested in joining a future workshop or webinar? Read this blog, contact us and start watching a free webinar recording about Next level performance testing in XC Skiing.


The workshop was part of a close collaboration between INSCYD and the German Ski Association. The goal of this 2-day workshop was to educate coaches and physiologists who are in charge of performance testing. Another goal was to increase the quality of future training programs and therefore future performance. The workshops also brought in athletes to the workshop as well to offer the athlete perspective on the covered topics.


The workshop began with a masterclass about the basics of applied exercise physiology. This introduction discusses the energy systems, including:

  • how the PCr energy system differs from all other energy systems, being discontinuous (like a battery or bucket of energy). And how it can only be recharged by the aerobic energy system
  • how the anaerobic glycolysis uses glucose and produces lactate. Why lactate is not a bad thing, and how pH levels have a huge influence on the energy production rate of the glycolysis
  • what limits the aerobic energy system and how it affects fat & carbohydrate combustion
  • After the basics, we dive deep into important details, and debunks some key misunderstandings. One example of the latter is taking a look at the energy containing molecule, ATP (Adenosine Triphosphate). Contrary to what some textbooks seem to say:

    Sebastian Weber talking at the INSCYD workshop for the German Ski Association

    “Muscle ATP concentrations do not change during exercise” – lesson 1

    There is one exception. During total exhaustion, ATP concentrations can decrease, but only a little bit.

    Coaches and federations interested in a workshop / collaboration, please contact us.   Many federations including Triathlon Federation Flanders, Belgian Cycling, German Swimming Federation and German Triathlon Federation participate in INSCYD workshops.


    While theory often applies to all sports, it’s the application that needs a sport specific approach. As you can imagine, that is when it all comes together and the details and undertanding matter most. Therefore, the second part of the workshop is all about use cases.

    Example: how to create interval workouts and training programs, based on VO2 and lactate. Knowing the oxygen uptake and lactate production of an athlete can highly individualize work-to-recovery ratios, because:

    “The ability to recover from a lactate accumulation, depends on the oxygen uptake” – lesson 2

    We look at specific race moments in XC skiing, and what is necessary to survive those high intensity efforts. For instance: how much VO2 uptake and lactate production is necessary to win a certain race. When trying to figure this out, it’s important to keep in mind that for a given effort:

    The higher the VO2max, the lower the glycolytic power / VLa­max­ can be – and vice versa.” – lesson 3

    That is because a given energy expenditure is (mainly) composed of aerobic power and anaerobic power. The higher the aerobic power is, the less anaerobic power is necessary – and vice versa.

    For a given effort, the higher your aerobic power is, the lower your anaerobic power can be - and vice versa


    This blog briefly summarized some topics that are covered during this XC skiing workshop. Working together with all kind of sport federations excites us. That is why we are looking forward to hear about the (energy demand) challenges you are trying to solve in your sport. Let’s inspire each other to better map the capabilities of your athletes and improve their training programs. Fill out the form, mention your federation/sport in the message text box, and we will contact you!