Stryd Footpod Data, Two Weeks Later

With a couple of weeks of running with the Stryd Footpod, I now have substantially more data on my running than I did on day one, and I want to dive into what I’ve found.

First off, if the Stryd benefitted my training in any way, it’s that it got me to run a LOT more often. I previously ran more sporadically, and leaned more heavily on aerobic cross training (mainly with the spin bike).

In wanting to assemble more running data, I put the Stryd to use on a lot of shorter runs, mostly during work breaks. I now have a lot of 0.9-1.2 mile runs (1500-2000m) that don’t exceed 10 minutes, plus some slightly longer 15-20 minute lunch runs. As Vegas begins to warm up, these require more effort, plus I have to be mindful that I have to go back to work afterward so I can’t go hard and get sloppy, and the area where I work is somewhat hilly and at higher altitude… thus these have been somewhat easy efforts.

The tracker also tracks measured walks, and these often include momentary sprints as I have to cross streets quickly. So I have a lot of 10-15 second high intensity bursts included in the data.

As a result I have a large sample of shorter runs, giving a lot of consistency to the short-end data at least. I still haven’t taken many longer runs yet (I have yet to take a run longer than 5 miles since getting the pod), so that data is more limited.

Because of this short-haul-centered data, my Stryd Critical Power (CP) is measured somewhat low, and probably lower than my Critical Power actually is. Once I get some hour+ runs in, the CP number will likely increase.

One item that jumps at most new Stryd users is how low the recommended running power is. My first runs were in the 200-220 Watt range, and Stryd initially recommended my easier runs sit in the 140-180 range. Runs at this level felt like grandpa jogs and still do.

Perhaps, after moderated paced easy runs from doing Garmin training plans, I got accustomed to running at a higher intensity, and got away from the easier intensities I ran with in Chicago. While still living in Chicago I ran that easy partially out of necessity: I was often running from home and to some extent tired, so I had to conserve energy since I was above all else transporting myself home. But on the flip side I effectively trained so much at a suitably easy intensity, was thus able to run longer distances, and my aerobic fitness improved dramatically as a result.

Either way, my current 219 Critical Power seems somewhat low and might be. My measured Power Curve lacks longer run data, and the long end of the curve presumes I couldn’t maintain more than 180 W, which I know I could exceed without much trouble.

I did a 9/3 Critical Power test last weekend (which includes a max effort 9 minute run and a max effort 3 minute run mixed in with a longer easy run). This helped fill in some of the data. But the missing link is a longer easy run.

Also, since obviously I’ve been running a lot more than usual, I may also need to rest a bit. I know for sure I haven’t crossed into overtraining, as very few of these runs I’ve done this last couple weeks were particularly long or taxing. After some recovery, my overall easy running may get stronger. I imagine, however, that this will take some time to manifest.

As for other key pieces of data:

  • Ground contact remains somewhat high, averaging a few hairs over 300ms, though some of my better efforts have been in the 260-290 range. Recommended GCT is around 150-300. This means my steps are a bit heavy and pronounced, and over time I need to take lighter quicker steps. Granted, on most work break jogs I’m not particularly concerned with going fast, so it makes sense that the GCT would be higher on those.
  • Cadence consistently hangs around 165-170 spm, not too far from the 170-175 I consistently maintained during earlier Garmin training. But that is a bit slow, and like the above GCT data it shows I could move my feet a bit lighter and quicker.
  • Form Power is consistently around 72-75, which is rather high (good Form Power apparently is in the low 60’s). I also haven’t been running as regularly as before, and I’m running heavier than I previously had. So as practice increases and weight (hopefully) decreases with time, I imagine this will gradually improve. That said, also bear in mind that during work break runs I’m in work clothes and do have things in my pockets, so the extra weight could be a factor in this (though yesterday’s run in conventional shorts also had a high form power; however, it was also hot and I was going a bit harder than usual).
  • Vertical oscillation consistently remains in the 5.8-6.1 cm range, which is somewhat low compared to other runners who average 8-14. Higher can be a problem and lower is generally good, but as mentioned in prior posts too low a VOsc could limit overall running power since you return to the ground more quickly and easily. So ironically I may need to increase my VOsc a bit to maximize my power output.
  • Once the Race Predictor had enough data to produce output (this took a bit over a week despite multiple runs on most days), it predicted an agonizing 6 hour 22 minute marathon time, but also recommended running at 78-82% of CP, which for me at the time was recommended around 170 W… again, rather low and rather slow. Since marathons are my key this is a key piece of data, and also speaks to the effect of lacking long run data. The system presumes I lack the ability to maintain anything close to CP beyond an hour, and that’s obviously not true. After a slightly longer run this week, this prediction spiked to 5:45… still pretty brutal, but a sign that easy long runs will substantially improve this prediction.
  • Looking at more conventional metrics… my average heart rate for these runs have consistently been in the 130ish range, easy intensity. So I’m clearly not over/underdoing these runs. The pace has typically been in the 11’s and 12’s per mile, very slow easy jogs, with a few 10’s and 9’s as running by feel permits. I imagine this is a key factor in why the measured CP has been so low.

Future posts will address other topics, but with my Stryd being new I wanted to follow up on the data I had collected before moving on.

3 thoughts on “Stryd Footpod Data, Two Weeks Later

  1. […] where I just keep a workout like this simple. Also, I’ve mentioned before I’m using a Stryd and focusing on running power stats, so I typically will focus on my running power in these […]

  2. […] that I now use a Stryd footpod, and one of its many benefits is it calculates accurate running stats (pace and power) on the […]

  3. […] do still plan to attempt long runs on the treadmill since my Stryd will allow for distance to be accurately tracked… a far easier and cheaper effort than trying to […]

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