Data Driven Coaching - Stryd Running Edition

Hello, athletes.

I recently sent an e-mail to one of our athletes and thought it would be a good way to start off the blog section of our website. Most of you who have worked with me in one capacity or another know that I am a very data driven coach. I don’t think this is better or worse than other coaching styles, but I am here today to try and prove to you why it can be incredibly beneficial…

Often times, you will hear about two different styles of coaching. One is very data driven whereas the other is very “intuitive with the body”. Like most things in life, it really isn’t so black and white, it’s more of a spectrum. You may have coaches who use data as feedback or for prescription purposes, they may want their athlete to use heart rate data (HR) along with Rate of Perceived Exertion (RPE), or you may have coaches who very rarely ask for qualitative data (how did it feel, how did you sleep, did you feel strong?) and only focus on the quantitative data (HR, Power, etc.)

Personally, I think it is important to be on the spectrum and focus on the “whole” of an athlete but I definitely tend to be more quantitative leaning in order to help me understand the qualitative… that may be the scientist and socially awkward nature of my personality.

Below, you will see some correspondence that I sent to one of my athletes who is using one of my favorite new pieces of equipment, the STRYD running power meter. Similar to a bike power meter, the data gathered from this device really benefits me as a coach. There is a huge benefit in “prescriptive” purposes for workouts, i.e. I want you to run between 160-170Watts for 45 mins, but that will not be the focus of this post.

Where Stryd really stands out for me, is the data gathered other than pure power numbers. Things like Leg Spring Stiffness, Horizontal Power, Ground Contact time, Vertical Oscillation, Stride Rate, Stride Length, and on, and on, and on. Here is a very small snippet of data that I use to work with my clients. Enjoy.

“Hey [athlete], 

Just thought I would send over some pictures to show you what I am looking at and why I needed access to all of your Stryd Data that I couldn’t get from Sunnto. As much as I love the power meters for the purpose of "power" data alone, it gives us a lot more data that I can use and I think you will understand shortly.

First, let's look at your overall data (including all runs with the stryd to date). Here I am looking at three main things. 1) Leg Spring Stiffness (LSS) - this is how well your tendons and muscles absorb and recycle energy without effort of producing new "energy". The higher the leg spring stiffness the better. 2) Horizontal power percentage (HP%) - This is a percentage of total power. For example, if 50% of your total power is horizontal power (the power that is propelling you forward) the other 50% is lost in form power (i.e. running in place) from excessive vertical oscillation, excessive ground contact time, etc. The higher the horizontal power, the better. Another "for example" if I have two runners, each producing 150Watts total power but one runner has a HP% of 80% and the other has a HP% of 65%, the one with 80% will win the race because their pace will be much faster. 3) Running Effectiveness (RE) - This is a more complex way of looking at running efficiency. This essentially boils many metrics down to a single number. The better the RE the faster you will be. This makes everything really simple, we can either improve physiology in terms of producing more power, or we can improve efficiency to be faster at that given power.

Ok, with those definitions, let's take a look at a bit for your data.

Figure 1: A look at LSS, HP% and RE in all runs over the course of January including individual data points and overall trend lines.

You can see here, that you have made dramatic improvements in horizontal power over the course of January. This paired with improved overall power has led to a significant increase in 5k time (01/19/19 - 25:39; 02/02/19 - 22:42). We do have a steady state LSS, which is not surprising because it takes quite a bit of work to strengthen the tendons and ligaments for improved LSS. This will come with training but can also be sped up using plyometrics (when we get there in our strength training). I will also talk about another thing we can do starting immediately to help speed up this process at the end of the e-mail. Finally, you see a bit of a regression in running effectiveness (RE) but that also is not very surprising. RE is highly dependent on training intensity. The harder you are working, usually the higher your overall RE. These data points include all runs and as we increase our long easy runs, this takes up a very large portion of our training volume, artificially lowering our RE. Which is why I have included the next figure.

Figure 2: A look at LSS, HP% and RE @ Critical Power (CP).

Here I have put on a filter to look at all of our data only on runs that fall within 88-102% of our Critical Power (CP). This means we are looking at runs within a relatively small window of intensity. Here, you can see that this essentially smoothes everything out quite a bit. When looking at our higher intensity, the first thing that pops out to me is that our LSS is actually improving while we are at intensity, which is great. Our HP% and RE is trending slightly downward based on the negative calculated slope. This taken with the last graph implies that our HP% is significantly improving at submaximal efforts (still really good for half marathon and marathon efforts). However, If you look at January 23rd, you will also notice that there is a bit of an outlier for an RE data point. This is one of your really easy support runs that was included in the data because of the average power was a bit high. After removal of that, all seems to be trending in the right direction.

Now, let's look at some individual workouts like your most recent long run. I am not going to define all of these variables because there are A LOT. If you want to know more about any in particular, just send me a message and I'll explain. I have broken this workout down into two phases. 1) Long Run Steady State (easy) and 2) Long Run Tempo. I do this because factors will change as you change intensity (stride length, cadence, ground contact time, etc.). Here we are looking at the trend line of a bunch of variables that indicate fatigue. 

Figure 3: Fatigue variables for the steady state portion of the athletes most recent long run.

I can sum this up very easily. It looks amazing... and when I say amazing, I mean amazing. You have very little if any degradation over this entire duration. This tells me that if we were strapped for time, we could comfortably increase the duration of this run over the recommended 10% ramp per week due to your current ability to absorb the training. We may even increase it a bit because you aren't getting enough of a training benefit from this run compared to breaking down a little.

Figure 4: Fatigue variables for the Tempo portion of the athletes most recent long run. Often, I include a tempo portion to finish my athletes long run in order to facilitate better aerobic adaptations and musculoskeletal adaptations. It’s not difficult to hypothesize that fatigue will be more prevalent in these sections.

Here, I would usually expect to see more prominent signs of degradation because you are running tempo at the end of a long run. Yet again, it all looks fantastic. Nothing that concerns me in terms of degradation in form. 

After looking at these two graphs, you may think we should ramp up our long run but I am going to try and convince you "not yet". The reason why I say this is because of our most recent 5km assessment [this email was sent two days after that assessment]. We made a huge jump in terms of our Critical Power (CP). Our next long run is going to be run at a much higher relative power and that may mean form breakdown a lot earlier. If I see a similar trend in our next long run, we may consider extending your long run. This is also going to be based on qualitative feedback from you. Did it feel good? Did it feel hard? Did it hurt? Did your form feel like it was breaking down (tight hips, quads, hamstrings, etc). 

Finally, I said I would talk to you about a way to start increasing our LSS before we get into plyometrics. We will start to see a benefit as we do more uphill running but a big and unknown trick is skipping. So, I'd like you to consider getting collagen and vitamin C. 60 mins before skipping, I want you to take two tablespoons of collagen and some vitamin C (usually in a hot drink like coffee or tea). Wait the 60 mins. Then skip rope (even if you don’t have rope just jump up and down like you are jumping rope). Start by 3 mins and work your way up to 6 mins maximum. Once you hit six minutes start incorporation some single leg skipping in that 6 mins and continue to build the length of that single leg skipping within that time. Try to do this 3-4 times a week. I would try and do it with your strength routine. DO NOT DO IT RIGHT BEFORE A RUN. If you are going to run that day, try to do it six hours before or after. Let me know if you have any questions.

Oh, almost forgot, according to my calculations you have about 62% Half Marathon Readiness with lots of time to go! So don't fret. You’re absolutely crushing this training.

—

Coach Tom”

TRI&TRI Coaching

Head Coach of The Aspen Triathlon Club

So, hopefully this helps convince you that there is definitely a place for in depth quantitative analysis behind “the art of coaching”. If you have any questions or comments, please feel free to message me at support@aspentriathlon.club

As always, happy training and stay safe out there! Also, check us out over at The Aspen Triathlon Club for live stream sessions and weekly training.

*Disclosure: I am not an employee of STRYD. I am listed as one of their coaches (someone who understands the analytics of the data obtained by the running power meter). I do not get paid by stryd, however, I do have a discount code for their power meters.

Are you a female athlete that is frustrated about the lack of discussion on how the menstrual cycle affects training? Check out our post here!