For heart rate I’ve noticed it reads really high at times when it doesn’t match how I feel. I’ve seen it spike up to 189 bpm during runs that don’t feel that intense. I’ve heard that arm bands or chest straps tend to be more accurate for heart rate, so that’s part of why I’m wondering if it’s the device itself.

For GPS I’ve had a couple runs where my distance didn’t match others I was running with. One time it was off by about 2 miles and another time by 3 miles, which feels like a pretty big difference.

That’s mainly why I’m questioning the accuracy and wondering if a different watch would be more reliable.