Gear & Technology, Podcast, Training

Triathlon Training with Power with Chris Myers, PhD | EP#305

 September 27, 2021

By  Bernardo Gonçalves


Chris Myers - That Triathlon Show

Coach Chris Myers, PhD, is the co-author of the book "Triathlon Training with Power", which brings together training with a power meter in not just cycling, but in swimming and running as well. In this interview, Chris discusses topics ranging from equipment and technology validity to training tips.  

In this Episode you'll learn about:

  • How to measure power in swimming: using the Trainesense Smartpaddle and the Vasa SwimErg
  • Use cases for training with power in swimming
  • The latest takes on training with a power meter in cycling
  • Running power meters: what do we measure and is the technology valid and reliable? 
  • Use cases for training with running power

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Chris' background

03:30 - 

  • I am doctor Chris Myers. I am a Master coach in Peaks Coaching Group and also an elite triathlon coach. Hunter Allen, who wrote "Cycling with Power" with Doctor Coggan, manages Peaks Coaching Group.
  • At the moment, I am in Germany. I am the human performance optimization program coordinator for the United States Air Force Europe for tactic operations. I do that during the day, and I am a coach at night.
  • A couple of years ago, people approached me to write a book about triathlon. There were a lot of books about triathlon training. But there was not a book on how to train with power for the 3 sports. 
  • Now, we have devices that can measure power in swimming, biking and running. And that is the goal of the book. It is bringing power theory to all disciplines so that a complete beginner can start training with power.
  • The book explains what training with power is, how to use the power devices. And the analysis we can do with such tools.
  • "Triathlon Training with Power" is almost the triathlon version of "Training with Power", written for cycling.
  • In our book, we have a chapter written by Hunter Allen.

Swim training with power

05:47 -

  • That is still an emerging area. There are two ways of measuring power in swimming: on land and on the water.
  • On land, the only option is with the Vasa Swim trainer. It is a swimming ergometer. It is like a rowing machine, but for swimming with a built-in power meter. 
  • This trainer gives you also left-right balance. Therefore, you can see if one arm is pulling more than the other. And it analyses your efficiency.
  • In the water, there is not a power meter device. But there is a force meter named Trainesense Smartpaddle
  • There is a distinct difference between a power meter and a force meter. But with some mathematics, we obtain the same power outputs.
  • The SmartPaddle allows observing the force you generate in the 5 phases of the stroke cycle. And it provides us data to analyze the force and arm movement direction. 

Trainesense Smartpaddle

08:03 -

  • For my athletes in the states and Germany, I send this equipment.
  • Each package comes with two small paddles that sit on the tips of the fingers.
  • They connect directly to the phone. It works by evaluating the way the flow moves through the hands. That is how it measures force. 
  • Every time the equipment gets out of the water or get close to the phone, it sends data. Therefore, we can have almost real-time feedback. 
  • In that way, I can evaluate each set while the athlete is recovering.
  • I send this to athletes that do not have access to a swim coach. And in that way, I can get biomechanical feedback based on these force meters, and we can do stroke correction. 
  • Typically, if an athlete has a high elbow pull, we see a significant increase in force. While with a straight arm, the force generation increase is slower. So, I can start working on improving the force generation of the catch.
  • The device measures the total force produced. It is a limitation, as it does not depend on the different angles of attack. 
  • Therefore, its use is optimal when applied with a side view of the swim stroke of the athlete.
  • Looking at the early Computation Fluid Modelling research 80% of the force is generated between the hand and the forearm. That is why the high elbow swim technique is more efficient. 
  • It increases that specific area of the arm. If you do that, you increase the force generation.
  • Of course, we also have to look at the hip position and overall body position in the water.
  • This equipment allows only to evaluate the force generation in the upper body.
  • Other accelerometers in the hips, knees and ankles could analyse overall body drag. However, these were not practical and were used only for research.
  • The difference between a good swimmer and a slower swimmer is the higher force production magnitude over the stroke. But also the way the athlete produces that force over the stroke.
  • A good swimmer has a faster increase in force, commonly seen in the high elbow stroke technique.

Vasa Trainer 

16:32 -

  • The Vasa Trainer is one of those items that we have to evaluate the cost versus the benefit.
  • They are great items, and there are a lot of versions. But the one with a power meter does cost between 1900 and 2500$.
  • It is a significant investment. However, it gives you a big return. It allows you to work on the different phases of the stroke individually. It also allows working on the other swim disciplines.
  • What it does is that you can sync it to a smartwatch and use platforms like WKO, and do an extensive analysis.
  • The trainer has two paddles connected to a turbine that produces resistance and allows to measure power. In that way, it only evaluates overall power production. Not horizontal power production.
  • The problem is that the athlete might not focus much on the high elbow catch because of the focus on maximising power production. 
  • It is an awkward position to be in because the athlete cannot rotate the hips. So the way I teach using the machine is by not doing the recovery part of the stroke. Because you will put a lot of strain on the back and deltoids, this can lead to an overuse injury in the shoulders.
  • So, it is pretty much advanced sculling: we work the extension, the catch, push and pull. And then, you bring it back up.
  • An athlete with unlimited access to the swimming pool could use the Vasa Trainer to do a resistance workout.
  • I have seen swim coaches doing five sessions per week. But as a lot of us are time-crunched, I limited it to two times per week.
  • Swimming with power is still in its infancy. What we did in the book was applying the cycling power theory to swim training.

Cycling training with power

23:00 -

  • Over the last five years, there was an impressive growth of power meters on the market.
  • Therefore, now there are a lot more types of power meters: crank-based, pedal-based, hub-based. Also, the price of the power meters has gone down significantly.
  • Before SRM, the industry provider and the standard for power meter accuracy would charge 2000$.
  • Now, you can get one for half the price and the same features or more.
  • A crucial development in the power meter industry was the introduction of the left/right power balance. Before, power meters would only measure the overall power, but now it is possible to look at the differences between each leg.
  • From that, we can see dead spots, how much power you are generating on the down and the up parts of the pedal stroke in each leg.
  • The developments lead to changes in the way I coach now, looking a lot more to the data analysis. The training theory of power training has not changed that much.
  • Of course, there have been some changes in the training zone definitions and specifics but they overall remain the same.
  • With the advent of platforms like WKO4, WKO5 or Golden Cheetah, data analytics have become the focus of my coaching related to cycling.
  • For example, in a 20 minute FTP-test, if the left leg produces 55% of the power output, it might be because of inefficiencies.
  • If there is an imbalance of above 3% (53/47), it is because there is a problem.
  • To solve that, we could do single-leg drills or check mobility issues and reevaluate the bike fit so that the balance gets perfect.
  • One tip for all the athletes is to analyze the past data to evaluate the progression over time.
  • A dual-sided power meter will depend on the investment, goals and our needs. A single-sided power meter might be enough.
  • Power in cycling is not all that matters. Learning how to train by feel is fundamental, as we should not follow blindly any power output.
  • Training with heart rate gives us also information on the way the body responds to certain situations.
  • Heart rate is a secondary metric for me, but its correlation with power is something we look into to get more information.
  • You should know your heart rate anaerobic threshold because it is an intensity, for example, in a time trial, where you might want to avoid going over.
  • I had a conversation with Ryan Bolton about Ironman races. One tip that he gave was to increase the heart rate in the final length of the bike slip. The goal is to help prepare for the running load.

Running with power

34:00 - 

  • It is a controversial topic. Power is work divided by time.
  • Therefore, there is a time component. When you break out work, you need to get it into the force equation.
  • In cycling, power is equal to force multiplied by cadence. Running is slightly different.
  • In the run, force equals mass multiplied by acceleration. Thus, your running power meters tend to be accelerometers instead of pure force-based (in cycling and swimming).
  • That is why, when using running power meters (for example, Stryd - the main power meter in the market), we should keep body weight consistent and up to date.
  • That affects the power that the devices show.
  • The two most sold power meters on the market are Stryd and RunScribe. There is a difference between the two.
  • Stryd is a single-sided power meter. RunScribe is a dual-sided power meter.
  • It goes back to the same question: what is better? Single or dual? The answer will again be the same as cycling (depends on goals, investment and needs).
  • The power equation in the run is equal to force (mass times acceleration) multiplied by the stride rate.
  • What running power meters measure is still not yet clear (mechanic power vs metabolic power). Only the R&D department of each of the power meter suppliers can answer this.
  • When analysing the run, there might be a correlation between the power measured by different devices.
  • However, the power read by Garmin devices is not measured directly but is calculated based on some estimations of arm swing and GPS data. 
  • Therefore, I would not compare the power given by Garmin to the one by Stryd or RunScribe.
  • I would also prescribe different training zones when using the devices because there are differences in the power measured.
  • When analysing data, you have the leg spring stiffness (LSS) calculation you get from Stryd. You also have "G", which is measured by RunScribe.
  • You have a couple of components when running. You have your "G curve" (impact G - the length of the entire curve; and the break G - the height of the curve).
  • They range anywhere between 4 and 13 G, depending on the source. 
  • If you have a higher G, for example, on the impact, you are more prone to a specific joint injury type. If the break has a high G, it means a possibility of more knee injuries.
  • There is a sweet spot between the two.
  • In RunScribe, studies measured G and LSS to compare it to the malleability of the muscle (the muscle acting as a spring).
  • As you get more and more tired, the stiffer you get. Thus, LSS increases over time.
  • When you accumulate fatigue, your form starts to deteriorate.
  • There are many use cases for these metrics, but I use them to evaluate fatigue. For example, when training for a 10-mile race, if the athlete's form starts to deteriorate at mile 7, you can check them in these metrics.
  • Even if the power of the heart rate remains the same, we can evaluate changes in run mechanics with this.

Benefits of running with power

44:00 -

  • It is perfect for pacing over rolling terrain.
  • It is one of the first you notice when starting using and coaching with power meters.
  • I admit it took me a long time to get on board with running with power. But, first of all, I just wanted to understand how the power meter works.
  • A watt is a watt no matter where you go. So, I can hold 300 watts on a flat surface or climbing up a hill. The 300 watts climbing is a lot harder than 300 watts on the flat.
  • Despite being the same power, you are fighting gravity. 
  • If you train by speed, 300 watts for you is a 7-minute mile on the flat. But it is complicated to know what it is on undulating terrain. Having power helps to manage the pacing strategy. Even if you slow down on the hill, you have a metric that can help slow you down to avoid going into the red.

Running economy 

46:15 -

  • Running efficiency does not exist. Running economy is the correct term. It is the efficiency of how you utilise oxygen.
  • How well are your biomechanics? How well your muscles contract. Your breathing rate. How hard you are working. All of that affects your run economy.
  • Training with power allows us to access the economy in the run. It gives you basic metrics (power, stride rate, cadence, stride length).
  • But, it also gives you advanced metrics (vertical and horizontal oscillation, LSS...). And we dedicate an entire chapter with case studies to break down these metrics, what they mean and how they can improve your run economy.

Using other metrics to prescribe run training

48:00 -

  • I primarily prescribe training with power because it gives a consistent metric, no matter the type of terrain.
  • However, covering the data and only analyse it later after the session also has value. It allows you to understand what it feels like to run at determined intensities. And become a bit more in tune with the different training zones.
  • Training with pace is still a powerful way to train. It is not as susceptible to external variables like heart rate is. But it is affected by terrain changes, wind direction. We only need to take into account the goals and what we should expect from each session.
  • And sometimes, it is fun to leave it all off and go for your Sunday run and enjoy the day. We simply need to make sure we bring the proper nutrition.

Recommendations to start training with power  

49:57 -

  • Before introducing any type of technology, do your research first. We have so many devices out there, so it is up to you to know if it does what it says.
  • You have to question if implementing the technology will improve your training.

Training tips for age group and amateur triathletes

50:57 -

  • First, do a needs analysis. I mean doing an honest assessment of yourself in the sport. 
  • You should identify your goals and if they are obtainable, tangible and realistic. You should set a challenging objective but that you know you can achieve.
  • Second, do your injury analysis. Are you susceptible to certain types of injuries? Do you have muscular imbalances? For me, I had four surgeries on my knee. Therefore, doing an Ironman might not be the best idea.
  • Then, do field tests to understand your strengths and limitations within all three sports.
  • Finally, structure your training according to your needs analysis. With this, you will be steps ahead of your opponents, following these steps.
  • The most important thing, in the end, is to plan recovery. Your body will not become stronger from hard sessions if you do not give it time to rest.

General question on coaching

 53:59 -

What would you tell yourself 10 years ago if you could go back in time?
If I could go back in time, I would tell myself to have confidence and not being afraid of failure. When I had my first client, I was scared of giving them bad advice. There is much education about training. But there is also a lot of trial and error. My physiology is different from yours. So each athlete will react differently to the same training program. If you feel something is not right, do not be afraid to change it.

What is one thing within coaching or training you are now learning/curious about or fascinated by and why?
Currently, I am looking now at glucose monitors. Those have been on the market for a long time for diabetes. However, Supersapiens was the first company to utilize glucose monitors to improve human performance. Signos is now coming in attempting to aid in weight loss (understanding how you react to certain foods or gels), helping tailor your nutrition better.


Bernardo Gonçalves

Bernardo is a Portuguese elite cyclist and co-founder of SpeedEdge Performance, a company focused on optimising cycling and triathlon performance. He writes the shownotes for That Triathlon Show, and also produces social media content for each new episode.

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