The heart rate data you see on the Stryd app is sourced from the Apple Watch on my wrist. Additionally, I run with a dedicated heart rate monitor strapped around my chest from Morpheus. This data is slightly more accurate and aids in tracking my recovery. *time is off because I start HRM a little earlier.
Interesting. I run with the Apple Watch and always looked to stryd, maybe this is the right time to seriously think to buy it.