Running, training and racing with power (Read 177 times)

I have the Stryd pod. The ability to run on a treadmill or indoors with it across the full pace spectrum without calibration is what piqued my interest. I am still absorbing the whole training with power aspect of it, which is convoluted and makes my head hurt.

Anyway, I had run with it outside using the GPS for pace and distance for the past week, and was all set to run with it using the pod for pace and distance instead of GPS for the first time this morning. The plan was to run with two watches to have the GPS variable there for comparison, except, I went into settings to find that I have been running using the pod for pace and distance for the entire week. It was the first or second day that I went into the stupid thing to see how all of that worked, and apparently didn't put it back to GPS before exiting the menu, ugh!

As it is, there was nothing about my paces or distances that led me to believe I was not running using the GPS. The splits of all of my various routes lined up pretty much as they always do. I did a pace ladder workout and nothing about it suggested the paces didn't correlate to the effort. Nothing about any of my runs was amiss, the thing was as "accurate" as GPS is.

So now I'll run with it using the GPS outside for a week, then do my little experiment of a side by side comparison with two watches next week. Gah.

I find that it measures shorter than the GPS on my watch. But that's not a bad thing, as my watch has frustrated me time and again by measuring races longer than they are, and therefore me being surprised that the finish line is actually further than I expected.

 

I noticed that you have concerns about what your GPS measures in a race.  In most circumstances the GPS should read longer than the advertised course distance and any intermediate mile or kilometer marks due to how race courses are measured.  All certified courses are required to be measured along the tangents (the shortest route a runner can take), but unless you are the only runner on a course you will likely not be able run the tangents.  Additionally all certified courses have a short course prevention factor (SCPF).  Basically all certified courses are intentionally made to be long.

That is not to say that GPS watches are perfectly accurate.  The GPS signal has its own error (typically + or - 10 feet) when determining a position and these errors may compound during a run.

 

I agree with all of this. My best watch was a FR 620. That watch measured courses pretty much spot on. A little long like what you're describing due to me not running the tangents, but I loved it. My current watch, not so much. It's a Fenix 3 HR. I don't know if it's because the antenna is buried under too much electronics, or the algorithm for curves smoothening has changed, or I just have a lemon... but it chronically measures too long.

Measuring long should be the usual with a GPS.  If you don't run tangents, that might add about 1% to the measured distance of the course.  Over a 10K, that means you will run 6.28 miles instead of 6.21.  At my pace (9:00). that's about 37 seconds.

If your Fenix does worse than that, then it's a problem.  I have a FR 35 by Garmin, and have also run with a 310XT and a couple other Garmin watches.  If I run a course with lots of 90 degree turns, my watch often measures shorter than the actual course, because the watch doesn't follow perfectly around corners.  And, sometimes there has been the urban canyon effect.  Occasionally, at the end of a device's life, it takes longer to get a GPS fix, and then there are issues at the beginning.  But, excepting the last one, I would say the GPS watches are within 1-2%, which is pretty good, really.  I had an older generation footpod by Polar, I think, at one time, and it was not as good because it calibrated to one pace, and there is a difference between running a track workout, and a tempo run, or running a long day or a very easy day in one's gait which that system couldn't deal with very well, unless I recalibrated every time, and I didn't want to do that, and neither do you.

I also use the Stryd footpod.  You have to have the correct watch or GPS will override the footpod's distance and pace measurement.  I have the Garmin Forerunner 935 and it allows you to leave GPS on while getting Distance and Pace from your footpod in all conditions.

If you are unsure if you are getting distance from the footpod, just rail the Calibration factor one way or another and go jog down the block.  Your pace will report either ridiculously fast or ridiculously slow IF its coming from the Stryd.  Then just set it back.

I would also recommend calibrating the Stryd at a certified track.  I calculated the distance of each line in between lanes and then ran on the line the entire way.  It's easier to follow a line than running 20 cm off the left edge of lane one (400m).

For reference, since getting my Stryd and calibrating it, I ran 3 races.  First race was a mile race on the track and it measured 1.01 miles.  I then ran a Half Marathon and it measured 13.12 miles.  Last weekend I ran California International Marathon and it measured 26.24 miles.  Average pace reported by my Stryd was identical to the pace on CIM's results page.  It's SUPER close.

The other nice thing about this is getting accurate treadmill reports.  It's really interesting to see just how far off some treadmills are in reporting pace/distance.  Some are almost exact but some will be over a mile off on a long run. Worst I saw was a treadmill that reported a pace 50 seconds per mile faster than what Stryd reported.  I knew Stryd was correct due to RPE and my heart rate.  Best I saw was a hotel treadmill that reported the exact same distance to the hundredth of a mile.

Anyway, just do a proper calibration and enjoy!

If you have any interest in Zwift run, the Stryd pod seems to be about the only reliable means of measuring distance/speed. I just wish they still made the cheap version, as I don’t need most of the metrics for Zwift running.

My husband is a cyclist and has always said the two best things he did for cycling were a good bike fit and a power meter. For cycling, when you're dealing with wind and drafting and hills, power is a much better metric than speed. So I've been intrigued by the Stryd, but so unimpressed with the foot pod that I have (Milestone pod which I think was bought by Zwift and is now the zwift foot pot), I haven't been willing to shell out the cash for the Stryd. Sounds like you're telling me it's worth it.

My husband is a cyclist and has always said the two best things he did for cycling were a good bike fit and a power meter. For cycling, when you're dealing with wind and drafting and hills, power is a much better metric than speed. So I've been intrigued by the Stryd, but so unimpressed with the foot pod that I have (Milestone pod which I think was bought by Zwift and is now the zwift foot pot), I haven't been willing to shell out the cash for the Stryd. Sounds like you're telling me it's worth it.

There are two aspects to the Stryd pod:

• The power meter
• The "foot pod" from which you get distance/pace

When running outdoors, you could continue using GPS for distance/pace and still use the power meter portion of Stryd if power is what you're after, but you're worried about a foot pod's accuracy.

Everyone I know ((I don't know that many people) find the accuracy of the "foot pod" portion of Stryd to be at least comparable to that of GPS. But, again, you get to choose if you prefer using GPS outdoors. It's definitely the most accurate foot pod out there. I had (still have) a Garmin foot pod for the indoor track, and Stryd is much better.

The power portion, I can't say if it's accurate or not. I find it seems to make sense the way the power reading increases when I go up a hill or run into a headwind at a fixed pace, like what your husband is describing. I have not raced with it yet, but I will, and hope that it will let me give a constant effort on varying terrain and conditions.