Field testing validation (Hoka, Stryd, RunScribe and more…)


Beautiful weather out here in Clearwater Bay. I set out to carry out a few simple tests I was meant to do for a long time already.

The plan is to run a few different pair of shoes across the track (same conditions, same pace, same speed…) and have a look at the data captured by STRYD powermeter & Runscribe sensors.

[Engineering background, I have always been into data analysis as a way to improve… “What gets measured gets improved” (from guru Peter Drucker) and purchased these awesome sensors long time ago in the Kickstarter phases. Both Companies in Boulder Colorado, probably one of the best places to live and work in the World! For sure on my bucket list to go live there someday…Even met the STRYD folks in Kona this year, replaced my old STRYD sensor with the latest one. Cool gesture, thanks.]



The plan is to run 5 laps around the track (2000m) at steady pace. I was thinking 4min pace (1’36 lap) but ended up running the first 2k in 7’30 so I thought I should aim for same time with every other shoes…2nd 2km went 7’42 unfortunately. Geez why am I so terrible at pacing today…I felt pain in my hamstring during the 2nd run so might be the reason I slowed down. For the last one the pain did not go away so I preferred to stop after 3 laps (5min approx.) and not make it worse…Anyway, I’ll have to repeat this field test someday and do it properly (4min pace sounds better to me too).

Oh…and yes, I took some rest in between each runs. Probably 5 to 10min. Next time going 4min pace may keep me in aerobic or tempo zone (steady state / no impact from fatigue).

I ran the ASICS GEL NIMBUS first (Excellent running shoes, cushioning but not oversized). Second I ran the ON Cloudsurfer (more on the minimalist racing flat style, although old model…) and finally I ran the HOKA Stinson Road 3 (oversized, one of my favorite shoe ever).

Still, the few results I collected were quite interesting…. Summary shown below:


I was quite surprised to find out a lower ground contact on the HOKA!? Maybe because I am used to run those shoes. But still, I went slower and at a lower cadence. Interesting. They may be simply more bouncy! Similarly to Newtons (that I should test out as well for reference).


Overall…I am looking forward to getting rid of that hamstring niggle to come back out there for some more testing!

Thanks STRYD & RUNSCRIBE for the sensors. It may not be 100% accurate, although the STRYD is quite impressive (exactly 2km!). For power, there was some wind and I am not sure it can translate onto the results…to be reviewed.


I also love the STRYD analysis about where I should focus, which is kind of true I reckon!


Nota: Leg stiffness is a measurement of how much energy a runner can recycle. The higher the better it seems. And consistent throughout the run is another key component.






2 thoughts on “Field testing validation (Hoka, Stryd, RunScribe and more…)

  1. Hi Erich, It is interestin g to see your data on the stride and the runscribe. I own a stryd for almost a year now and by comparison to others we now there is some difference between power calculated between different units. For a simmilar run as your second one I use only 300 W average of power which is a considerable difference, but seeing your heart rate being in a similar average beat I would guess the power in either of our units are a bit off. Nevertheless for internal reference the stryd is fantastic, informing you on your consistency.

    Why the hoka may provide more leg spring? you also bounce higher (VO = 0.9 cm higher), costing more energy to go up and being returned when you push off.

    Another thing to be considered is that we do not exactly know what and how leg spring is mleasured or calculated, is this the total of all flexors or just the spring in your achilles? I measured and compared with a friend of mine (using and exchanging Stryds in one session), and having VO, cadence, speed and contact time nearly identical, form power and leg spring were quite different for the both of us. I dont know what it tells, but I would stick to power and heartbeat for essaying whether something makes you go faster more easily. The rest of the data is modulated or derived in such a way that all variables can have such an impact that it is difficult to tell head from tails.

    my 2 cents, all the best,


    1. Thanks Patrick for your input.
      I am quite heavy (at approx 90kg) and that could explain why my watts are relatively high. Although Jim Vance did not advise to look at Watts/Kg as we do in cycling…(main reason if I recall correctly is that “all” watts in cycling are used to move forward while many watts in running are not productive (like you mentioned my vertical oscillations are quite high, not very efficient, and slow cadence too).
      Hans Van Djik (and his colleagues) did a lot of really interesting tests on power (See “the secret of running”), on treadmill / controlled environment. Next time I’ll try to do something more scientific on treadmill as well. I still rely mainly on HR but keep power input for reference. [3/9min all-out efforts to find out your FTP, or the 30min test…and compared with HR at http://FTP…]. Lots of useful information on STRYD blog as well.


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