@brady_h For sure the Coros Band has been good to me. seems more accurate than wrist from Coros Apex Pro. However Coros is coming out with new watch model with improved Wrist HR, interesting to see if as promised. But their band is comfy on the arm, I prefer over the chest band
@dpolehn sometimes its as simple as if you can chat, its a chill run, as you start to gasp, its getting harder (tempo-ish), when you have to start to concentrate on breathing /form, its starting to cross over to threshold/race pace. After that, you hit the leg moaning..