In this Episode you'll learn about:
- The Power Duration Model
- Key features for triathletes: Stamina, Time To Exhaustion, and Individualized training zones
- WKO4 for running with power
- How to use the information from WKO4 to drive training decisions.
What is WKO4?
- WKO is a powerful analytics software for endurance athletes.
- It is a partner or a sister program to TrainingPeaks. TrainingPeaks is a calendaring and planning system. Then WKO handles the analysis and analytics.
- WKO4 is the newest version of the product. It is a radical upgrade to the WKO product line. It is an analytics engine and a big shift in the way that we look at the analysis.
- This is a tool that allows the vast amount of data in the endurance world to become actionable. We can collect all these different pieces of information – what’s coming in, what’s happening, what’s occurring – and then find a way to turn that into actionable data.
- This tool gives you insights into improving your training methodology. It monitors your response to exercise stimuli which gives a deeper insight into the dose-response mechanism of training.
- This tool enables you to analyse what you’re doing, measure its effectiveness, and improve upon that.
How is WKO4 applicable to triathletes?
- When we originally designed WKO4, it was driven by the cycling community.
- In the last 4-5 years, data really deeply entrenched itself in triathlon in addition to cycling. You’ve always had power training and heart rate data at a high level for cycling. We’ve seen over the last couple of years the introduction of running power meters. Now we’re going to be seeing more and more the introduction of even swimming power meters.
- We had anticipated this development. So, when we launched WKO4, the data for cyclists was more readily available to be able to maximize the program to get to those actionable items that you wanted to see. The triathlon market has quickly caught up with this.
- Now, our fastest growing market of WKO4 use is our runners and triathletes, not cyclists. As the robustness of the data available from multi-sports is really trickling into the marketplace, the need for that analytics is there.
- What WKO4 is really teaching the triathlon community is that understanding the physiology going on underneath is crucial to improving the effectiveness of training.
- Think about training as a 3-step process. First, it’s a stress – an external measurement. So you apply stress, a power number of how many watts am I riding my bike or how many watts am I running at? Pace is a stress.
- Second is strain. This is what your body is going through when it’s under stress. This is what really drives adaptation, which is the final step.
- So, you apply stress. Your body goes under strain and then you rest. Then you adapt and get faster.
- As a professional coach for many years, I’ve seen people think that the steady state performance of triathlon was just about a linear approach. If I need steady state, all I do is train steady state and my physiology, my stress-strain-adaptation relationship will be very linear. I apply the same stress. I go under the same strain. I get the same adaptation.
- WKO4 gives a physiological look through the use of a powerful modeling system. It gives insights into the physiological adaptations that are happening underneath.
- This improves the coach’s or the self-coached athlete’s understanding of that stress-strain, which is typically called dose as a group, and therefore also understanding better the response. This allows for an improvement in training.
- Triathletes are the most time-challenged, having multiple sports to prepare for. All great training is, is the highest efficiency for the least amount of time.
- What WKO4 does is it makes you more effective. It allows you to target your training in all disciplines for a higher effect for potentially less time and fatigue. This allows for more quality training, rest, and better adaptation.
How do you look at your physiology and how do you then use that to drive your training decisions?
- WKO4 is an analytics engine. The difference between analytics and analysis is that analysis is basically looking at the data and looking for meaningful patterns.
- Analytics specifically looks at the pattern. Instead of just finding a pattern, analytics says very specifically, "you did this and you got that".
- Three abilities drive an analytics engine. First is modeling. WKO4 uses a very powerful human performance model known as the power duration curve that was designed by Dr. Andrew Coggan, Tim Cusick, Hunter Allen, and Kevin Williams.
What is the power duration curve?
Power Duration Curve - Click to zoom
- It’s a mean maximal performance curve that can be power or pace. It tends to be power because it’s the cleanest data.
- It is a second by second model that shows your degradation of power, pace, or speed. If you looked at 1 second, you’re looking at a very maximum number.
- However, the reality is that you can’t sustain that as an athlete, you drop off. This drop off looks like a curve. It’s sigmoidal in shape.
- This basically tails out from a very high ratio in a few short seconds to high power, high pace. You could sprint for a couple of seconds much faster than you can run for 20 minutes. Then it quickly drops off all the way out to minutes, hours, and potentially even days in the curve.
- What it is measuring is the maximum amount of power that you could put out over time.
- When you say power duration curve, you’re looking at it in the sense of power created. But what you are really measuring is how much you fatigue. That drop off is the fatigue rate of maximum power, speed, or whatever you’re putting out.
- Having this accurate second by second model allows you to build physiological models. When we built this model we spent a lot of time making sure we connect it to the way the body makes energy.
- We can use the power duration model to take a very broad 360° view of your performance capabilities. We can look at your Pmax, functional reserve capacity, functional threshold power, time to exhaustion, stamina, and VO2max to create this ability to look at you as whole athlete.
- A lot of triathletes do a lot of work off of one physiological metric which is threshold. A lot of your training is a percentage of threshold or a training zone based on threshold. By using a power duration curve, you’re not just seeing that one target moving, you’re actually able to extract different types of physiology – maximum power, anaerobic and aerobic capabilities, stamina, time to exhaustion, etc.
- As you’re doing work and introducing exercise stimuli, you’re getting different responses. You’re physiology changes. You don’t just get more fit, the type
of fitness you have changes. That is only half of what it’s doing. The other half is how you can connect that to desired performance.
- Understanding these analytics by going backward and looking at it you can see not only what physiological changes occurred when you introduced a certain exercise stimuli. But you can also see how that specifically related to performance. What you’re getting now is predictive analytics.
- Once you understand the analytics and the history of your performance, you can then replicate and improve on the good stuff and hopefully drop the bad stuff.
- Once you begin to track these, you can make significant changes to your training regime to dramatically improve how effective it is.
What are the key things triathletes can look at within the model to reverse engineer performance?
WKO4 key metrics bar - Click to zoom
- Within the power duration model and the physiological metrics that we’re tracking, there are 3-4 metrics that are very important to triathlon.
- One is functional threshold power. This is your aerobic endurance, the maximum amount of steady-state effort that you can hold. It directly relates to your maximum lactate steady state.
- We also have time to exhaustion which is how long you can sustain that maximum lactate steady state before you begin to degrade.
Time to Exhaustion (TTE) Curve - Click to zoom
- Then we have stamina. This is probably the most important starting point because this is your long-term steady state. It’s a degradation of performance after one hour. In its simplest terms, it’s a percentage of drop off.
Stamina chart - Click to zoom
- As a triathlete, particularly doing longer distance events like an Ironman, it’s really important to understand stamina because it rolls muscular endurance, energy management, etc. all together into a muscular metabolic summary. This gives you a measurement of how well you can sustain after an hour and over time.
- Once you understand stamina and see how your training affects your stamina, then you would want to see the interaction between the other physiological metrics such as functional threshold power and time to exhaustion.
- There is a high correlation between increases in functional threshold power and stamina performance. Traditionally, we tend to think about stamina as sustaining. A lot of the training is all about sustaining a pace.
- This has led to some continuing improving training mechanisms where there’s a little more focus and introduction of more work specifically related to improving functional threshold power.
- When we talk about sprint triathlons, I would pay more attention to VO2max which is your maximum aerobic capacity. It’s how much oxygen you can utilize - intake and uptake. It is how much you can breathe in and get in the system and how much the system can use.
VO2max chart - Click to zoom
- As you train, VO2max will change. The reality is that if you can improve VO2max, you’re actually raising the ceiling a little bit and you’re leaving more room for threshold growth underneath.
- We actually find that for shorter events like sprints, that higher VO2max is allowing people to operate at a higher percentage of FTP throughout the event and leading to some improved performance.
- I see it as tweaking some individuals’ training to give more focus towards racing that VO2max as part of the overall relationship with threshold and stamina.
- So we’re seeing a little bit of evolution of finer tuning between the longer distance events and the mid and shorter distance events.
Is there room for using time to exhaustion in triathletes?
Time to exhaustion (TTE) is highly sensitive for triathletes. When data is sensitive it means that small data inputs can cause larger changes.
- If you have a small change, like a 5-watt improvement in threshold, it could really change your time to exhaustion by 10 minutes or so.
- Most people who train with power are quick to tell you that 10 watts can be all the difference in the world for a triathlete between not being able to run and being able to run successfully. In a cyclist, 10 watts can be all the difference in the world between sustaining a great time trial and blowing up two-thirds in.
- Basically, for me, I use time to exhaustion as part of my phases of training. In certain phases of training, I might not care much about time to exhaustion, when I’m really working on the development of threshold and stamina.
- If you’re doing shorter events like sprints, as I get closer to the event, I become TTE-sensitive to that performance. I’m trying to find at what point that person begins to degrade.
Using WKO4 for running with power
- There’s a difference between cycling and running with power that you need to understand to get running with power right. When you’re cycling, you’re creating energy in a very efficient way. This reality is not true when you run.
- Running power is susceptible to running form. Therefore, there is more individuality in running power than cycling because you don’t have the bike which gives you the mechanical advantage of efficiency.
Running with Power chart - Click to zoom
- When you fatigue in the run, you have way more drop off in power. Learning to control your gait, pace, and stride to maintain a running efficiency is really important because the first thing that a power meter is going to tell you is how fatigue affects your efficiency over time.
- So if you understand this as a background, what WKO4 has done for runners and triathletes is that it allows you to understand the effects of factors like fatigue.
- You can measure fatigue in a lot of different ways with WKO4. You can measure it as simply cumulative work, cardiac drift, or aerobic efficiency. Pick whichever one works for you. When you compare that, you see a significant difference in the efficiency of the bike and the efficiency of the run.
- Now that we’ve learned what the data is teaching us with all these running power meters, there’s a lot more focus on not only using the power meter to measure performance and work in training but actually a more specific tool for measuring efficiency.
- This gives runners not only an improved efficiency, gait, and fatigue look through the software, but more and more devices are going to try to give you more real-time feedback in your running.
- If we know that running declines as you fatigue, your efficiency goes down X amount. It’s not all about the power in running. As a matter of fact, efficiency is more important than power.
- We did a study on a bunch of triathletes participating in Kona. We were measuring their running power and efficiency. Eventually, everybody’s pace comes down to what they can do efficiently.
- They might have started at a certain pace but they quickly settle into a pace that’s right in tune with their running power efficiency, which professional triathletes do so well. The reason for this is that one, they’re trying to be very efficient. Two, it’s unsustainable if you’re pacing above that efficiency, you’re fatigue rate is so much higher.
Features of WKO4
- Power duration curve model. This allows us to individualize your training. This is the driving theme of WKO4.
- iLevels. These are training levels or zones which are not just based off a percentage of threshold, but points on that power duration curve. So it’s totally individualized to you. It moves away from the idea that things are a percentage based on functional threshold power. It individualizes by the physiological event you are trying to improve.
- Optimized intervals. Since we have this model and we have a whole bunch of historical data on the athlete that we can crunch, we can actually mathematically see inflection points which are a type of time and effort that you’ve put out historically that has most impacted your fitness. So if you just want to look at what is the ultimate interval, how much power over how much time if I want to improve my maximum aerobic performance. Well, we can tell that’s exactly 4 minutes and 20 seconds at this power with a very tight range because we have your model, we have your numbers pretty locked in.
Optimised intervals - Click to zoom
- The power duration curve model, iLevels, and optimized intervals are the three individualizations. These then lead to the Performance Management Chart. With all these individualisations you can then track performance over time in a multi-sport or a single sport. This allows you to use chronic or acute training load and training stress balance typically known as fitness freshness and fatigue to understand how you’re building and utilizing how much training load or fitness.
Performance Management Chart - Click to zoom
Favourite book, blog, or resource related to triathlon or cycling:
Favourite piece of gear or equipment:
A personal habit that helped you as an athlete:
- Posting goals, recording, and using the data itself as motivation and not just as tracking.
Links, resources and contact
Links and resources mentioned
Connect with Tim Cusick
Connect with host Mikael Eriksson
Hi! I'm your host Mikael,
I am a full-time triathlon coach and an ambitious age-group triathlete. My goal is podium at the Finnish national championships within the next few years.
I first started the website Scientific Triathlon in autumn 2015 as a passion project to share my learnings with a larger triathlon audience. Later on, in early 2017 I started the podcast That Triathlon Show.
I sincerely want you to contact me to
- Send me feedback
- Give constructive criticism
- Request topics and guests for the podcast
- Send me your triathlon-related questions
- Tell me that you've rated and reviewed That Triathlon Show so I can give you a shout-out on the show and tell you how much it means to me!
Subscribe to That Triathlon Show and never miss an episode!
MORE ON THAT TRIATHLON SHOW