The RW (running wife) added a Stryd Light to her arsenal to get better pacing and distance. I’ve been very happy with my Stryd, it’s precision is pretty phenomonal compared to GPS. For example on our recent 20 mile run, it measured 10.1 miles out and 10.1 miles back and the start and stop were within 2 meters of each other.
While you ‘can’ run with a Stryd out of the box with a calibration of 100% I believe you really do need to run a calibration run with it. For instance during our races she was coming up slower than me and her distance was shorter (obviously).
The calibration is to go to a 400 meter track and run 4 laps and the distance should be 1600 meters (duh) then run 8 laps and the distance should be 3200 meters. If you get less or more than those values then divide the desired number (1600 and 3200) by the actual value. And then move the decimal two places to the right.
Example: You should hit 3200 meters but you ended up with 3100. So divide 3200 by 3100 and get 1.032. Move the decmial two places right and get 103.2. Plug that into your calibration value. Now your measured distance will be multiplied by 103.2 percent and you should be on the nose. If you measured high, like you got 3250 meters and it should have been 3200 then 3200 / 3250 = 0.984. Move the decimal two places to the right and you get 98.4 as your calibration value.
After running the calibration I believe she ended up with calibration of somewhere around 101.7 which sounds pretty close to what she should have comparing hers to mine during the races.
My calibration is currently 99.1. I also ran (re-ran) a calibration run yesterday of 6k. I lapped at 4 laps and had 1.6K (400×4 = 1.6K). I then lapped at 9 laps and had 3.6K (400*9) is 3.6K. Those were around 11:00 minute miles. My ankle and arch is still bothering me. And I weight 250lbs. Don’t judge me. After those I did one lap at a walk of about 16 minute and ended up with .39k so it was a hair short. Then I did 1 lap at a 7:00 minute mile and had .4k. I’ve seen for a while that the Stryd doesn’t register quite as accurately for me at a walk as it does at a run, it always reads a bit short so the .39 was expected.
We still have some training runs to do so we’ll see if we’re closer to the same ballpark when we run together.