Podcast, Training

Training Talk with coach Mark Pearce | EP#247

 August 17, 2020

By  Mikael Eriksson


Mark Pearce

Mark Pearce is a triathlon coach with a strong background in physiology and sports science, including working as the physiologist of the British Triathlon Olympic team from 2002 until 2010. He has been to three Olympics (2004, 2008 and 2012) as physiologist and coach, and brings a wealth of experience from high performance sports, that he now applies to both professional and age-group triathletes in his coaching practice.

In this Episode you'll learn about:

  • Mark's coaching principles
  • Interval training
  • Periodisation
  • Heat adaptation
  • Training intensity distribution

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03:30 - 

  • My background is as a physiologist and I actually started working as an applied physiologist within sailing, which isn’t the most obvious choice.

    Later I came to switch to triathlon and have had plenty of different ”titles” during the years within British elite and Olympic triathlon.

    For a long time I was also the head coach of one of Great Britain’s high performance centers.

    In recent years, however, I have switched to coaching more towards long and middle distance triathletes, both professional and age groupers as it has been easier to combine with a family life.
  • My own sporting background is as a cyclist, but in my mid 20:es I realized I wasn’t going to be good enough and that’s when I decided to enter the field of sports science, applied physiology and coaching instead.

Coaching/training principle/philosophy

06:45 -

  • As a scientist and coach I see myself as a problem solver, athletes come to me in order to improve and I analyze every athlete individually and try to find out what the best strategy is for this particular athlete.
  • I work in very close collaboration with my athletes, I want them to be engaged in the process in the same manner as I am.
  • During a time I worked very closely with Joel Filliol, which is one of the high profile coaches within triathlon at the moment, and I try to adept his approach of getting the best possible response out of as little training as possible, this becomes even more important when working with time crunched age groupers.
  • One of the most common mistakes I see athletes do is being too affected by social media and what other athletes are doing and testing, this leads to them wanting to try new things all the time without really following through the initial idea or plan.
  • I have also noticed that many of my athletes have actually been able to improve substantially this year when we have had no races to engage in since the consistency in the training has been so much higher.


11:35 -

  • I do not have a general structure that all my athletes follow in terms of periodization, it all depends on the athlete’s profile, race distance, time available (age group v.s. pro etc.).

    However, my default way of approaching a seasonal training plan would be a reversed type of periodization.

    This means that you start early by having a rather polarized training with really high intensity (like VO2max intervals) mixed up with low intensity volume training.

    Later on I put in a period more focusing on fatigue resistance and building threshold.

    Closer to race date, for longer events such as the Ironman, I make sure that my athletes are accustomed with the planned race power and/or pace neurologically as well as mentally.

    During this block we also do plenty of testing on how well the athletes can keep their target race pace to evaluate if it is reasonable or not.
  • Normally, one focus block, like a ”VO2max block” is around 8 weeks long, which is the amount of time needed to establish a proper respons.

    However, when focusing on sweet spot or hard endurance training, I tend to prescribe rather shorter blocks since this type of training generate a lot of fatigue and keeping up with that training may only make the athlete more tired and not actually fitter.
  • In terms of VO2max, you can either improve VO2max by doing plenty of high intensity training or do plenty of volume at a low intensity, in my experience I tend to see a quicker respons on VO2max following high intensity training but this effect is much easier reversed compared to the gains in VO2max by plenty of volume training.

    This is maybe the reason for why a polarized training approach is thought to be so successful, since you target both ends of the VO2max spectrum.

Volume and polarized training

23:50 -

  • When discussing training volume and polarized training, the 80/20 ratio often comes up as a mark to strive for.

    However, this mark is often withdrawn from elite athletes who have a huge total training volume, which makes the total amount of time spent in the high intensity (above threshold intensity) zone also very high if 20 % of their total training time is performed here.

    This raises the question to me if the reason for why these athletes are so good because they apply a polarized training strategy or simply because they spent a lot of time or kilometers at high intensity?

    I think that most age group athletes would benefit from doing slightly more than the suggested 20 % of their training as high intensity to get a proper adaptation to training.

    Also, when it comes to volume training, I believe that most age groupers need to do their volume at a slightly harder intensity (but still in zone 1 in a 3 zone system) than many of the elite athletes to get the desired response.

    For instance, many athletes have their LT1 at around 70-75 % of their max HR, this intensity is not super easy by any means even though they would still be in their zone 1, an age group athlete who would ”only” have time to bike 4h a week can load wise easily manage to keep around 70-75 % of HR max on his or hers endurance training, for a professional athlete, however, who trains 12-13h a week on the bike could impossibly be able to keep 70-75 % of his or hers HR max as this would equal riding at maybe 300w+ and/or 40 kph+, which would be too metabolically demanding and/or technically difficult.

High intensity intervals

33:25 -

  • We think that for open water swimming, the pool training is most important, hence, all dry land training is focused on being able to get the most out of the pool training.

    Therefore, our dry land training is directed towards injury prevention and core stabilization since having a firm core is a key to be able to swim in the pack in an efficient way and not get tossed around too much from the other athletes.

    Example of strength exercises that we use are the redcord system, versions of the plank exercise etc

    When it comes to injuries, our greatest prevention measures are directed towards shoulder injuries, since they tend to occur quite frequently among swimmers.


38:00 -

  • I have found that nutrition needs to be super individualized since different athletes can have massively different metabolic profiles.

    For some athletes, me included, being able to replenish a large amount of carbohydrates during hard and big training blocks is absolutely necessary in order not to blow up 2 weeks into the block.

    For other athletes, and this is for those who have a great capacity to oxidize fat as a fuel, carbohydrates does not seem to play as large role for their recovery as for someone like for instance me.
  • In many cases, it comes down to the athletes’ ability to utilize fat as fuel in order to what type of nutrition strategy that should be implemented for the particular athlete.

    For Ironman athletes with a poor fat oxidation capacity, then this needs to be improved and then certain periods with low carb diet can be one way of addressing such an issue.
  • In summary, one needs to look at the individual’s specific metabolic profile and tailer the nutrition to that as well as the certain demands of the event that the athlete is targeting.

Heat adaption

45:30 -

  • In Britain we have always used plenty of heat chamber works.

    And I have always been an advocator of doing high quality sessions in the heat chamber.

    I have also noticed that many athletes do perform significantly better in cooler climate after doing specific heat work.

    When you’re in a ”heat adaptation period” I normally recommend doing around 3 sessions per week in the heat chamber.
  • One another important aspect to consider is to make sure to be specific in your heat adaption process, if the race is taking place in a dry but really hot climate, then you need to prepare for that and if it instead is really humid but not extremely hot that requires another special adaptation.

Transitioning from draft legal races to middle and long distance racing


  • The level of middle and long distance triathlon have increased significantly in the last couple of years.
  • Naturally, the bike needs to be emphasized much more when transitioning from ITU to middle and long distance events.

    For most athletes, the swim volume will decrease when transitioning, which is also true for run volume in most cases.

    Many ITU athletes run between 80 to maybe 110 km per week and Ironman athletes typically run 60-80 km per week (very few sustain a run volume of over 100 km per week over a longer period of time).

    It’s also a big mental transitioning, one needs to be prepared to go fairly hard for a much, much longer time when racing non-draft legal races.
  • When it comes to age groupers, I think most of them would need to increase the volume a little bit (on the bike and in the run) as well as getting used to control their intensity in a much more diligent manner.

Tips for athletes and coaches from a physiologist

1:02:55 -

  • I believe that for being able to succeed as an athlete, you need to have a fairly good basic knowledge of human physiology and exercise physiology, this will help athletes massively to understand what is going on in their bodies.
  • Another important aspect is to be really diligent when it comes to planning and goal setting, I would like my athletes to be really clear on what they want to achieve so that I as a coach can plan accordingly.

Rapid fire questions

1:05:25 -

  • What is your favorite book, blog or resource related to swimming or endurance sports? I don’t have a favorite all time resource but at the moment I have ”Strength and Conditioning for Endurance Runners” by Richard Blagrove and ”Strength and Conditioning for Cyclists by Phil Burt on my desk, which are both a good read!
  • What is your favorite piece of gear or equipment? I don’t have a favorite piece of gear or equipment but one favorite at the moment is the Stryd running power meter.
  • What is a personal habit that has helped you achieve success? Organization and the planning side of things, being able to see the picture and pull it together for the athletes.


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.

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