FWIW - Surprised at how well HR and Stryd Power tracked together on an easy run (Read 49 times)


    Hi - I've been using a chest strap for HR, and today was my first run using Stryd to calculate and display power. I'm a lowish-level recreational runner, 59 years old, with a recent 5K time of 26'15", and 10 years ago a marathon time of 3:43 (iirc). This post is just to share an observation I made today, the first day I used Stryd Power during a run, but it's really nothing earthshaking at all!


    Anyway, for the last month or so I've been using HR to guide my "easy" runs, and have decided recently to keep them between 140 and 150 BPM for a while (78-85% of my true max HR). Today, every time I glanced down at my watch for HR on the 5 mile run, I also looked at the Stryd "Power" display. There was of course variation in each, but I was kind of thinking that they seemed to not be going off wildly in opposite directions, "... hmm, they seem to be listening to each other", you know, the kind of half-thoughts you get when you're running.


    When I got back and looked at the Stryd Power Center is where I was very surprised/impressed:


    1) Keeping the HR in the range I wanted resulted in my pace being almost completely even over the 5 miles - each mile "lap" was within 10 seconds of all the others. Nothing to do with Stryd, I know, but I'd never noticed that before. Takeaway message for me - at least on this course (one quick hill up, then a long hill down, otherwise flat) that keeping HR flat meant keeping pace flat. Who knew!


    2) More to the point re: Stryd - My Power for each mile lap was remarkably similar to the Power for any other mile lap. Takeaway message for me - HR changes being flat/minimal predicted Power changes being flat/minimal, and vice versa, when averaged over a mile distance - at least on this course. (FWIW, "Form Power" and "RSS" were virtually identical for each of the 5 miles as well).


    I don't know if that means that, at least on this course, Power is not adding anything to help me run that HR isn't already adding - i.e., monitoring Power has little incremental benefit over monitoring HR alone.


    I'm a newbie in many ways to all this, so if someone wants to make a comment and/or correct me, I don't mind!


    Cobra Commander Keen

      I've run with Stryd for a little over 18 months, and here are my big takeaways:


      HR and pace are merely a reflection of effort, while power shows the actual effort. For instance, on a flat course at a given pace Stryd will show whatever number of watts it takes for you to hold that, but it may take several miles at that pace for your HR to reach a steady level and stop climbing. So if you run a mile warm-up at 9 min/mi Stryd will show one number for that, and your HR will also reflect the effort. Speed up to a tempo at 7 min/mi (just pulling numbers out...) Stryd will instantly jump up to show the increase in effort, while your HR will gradually climb up until it levels off.

      The real power of running using Stryd (no pun intended) is in pacing on hills. Heart rate will always lag behind the effort you're putting in, and (compared to running on flats) pace will always be slower than the equivalent effort when going uphill, and faster when going downhill.
      My critical power (about what I could run at for an hour) is ~305 watts. If I concentrate on hitting that number when going up or down hill, my percieved effort will be pretty much the same as it would be if I were on a flat trail, even though my pace will likely be quite different. And that's the key - training by effort, rather than by pace. If you use Strava, compare the GAP for a certain wattage on an uphill to the pace on flats with the same wattage - in my experience they're quite close together, usually within ~5 sec/mi.



      It takes a while, but learning the wattage you can sustain for different race lengths greatly helps with pacing. Just look at the number from Stryd (I typically use 3 or 5 second rolling average) and forget about pace entirely. It helps you to stop from going too hard early in a race or up hills, while helping keep you honest in your effort - if you know you can hit xxx watts for a certain distance there's no reason to let yourself just cruise below that number.

      5k: 17:58 11/22 │ 10k: 37:55 9/21 │ HM: 1:23:22 4/22 │ M: 2:56:05 12/22


      Upcoming Races:


      Wurst Race Half - Oct. 7
      Heartland 100 - Oct. 14



        Whether these running power meters are useful is still open to debate. Here is an article I've found illuminating.




          Whether these running power meters are useful is still open to debate. Here is an article I've found illuminating.




          Thanks for that link! I didn't get the impression the author was questioning whether it was useful, but rather pointing out that there are a lot of behind the scene data massaging to make it work.


          Whether it's useful or not I suppose is best answered with a comparison between two groups' race results - one training/racing "with Power", one conventionally. In the absence of that, anecdotal testimonials seem to be almost entirely in favor of Power training/racing being helpful. Confirmation bias is likely huge there, but what can you do!