Reccomend a cycle computer

[si_c]

Assuming your watch supports external devices then you could use a chest strap version that actually works rather than the dodgy wrist based measurement that it not accurate when cycling.

They're not too bad actually, I tested my forerunner against a chest strap and it was only a couple of BPM out, although it did take a little longer to respond to efforts.

It's good enough for me that I'm happy to use it in place of a chest strap on shorter rides (sub 2hr).

 

[Milkfloat]

They're not too bad actually, I tested my forerunner against a chest strap and it was only a couple of BPM out, although it did take a little longer to respond to efforts.

It's good enough for me that I'm happy to use it in place of a chest strap on shorter rides (sub 2hr).

My current Vivoactive and previous Forerunner were miles out, at least 20% under-reading. It seems to be be variable on your wrist position.

 

[si_c]

My current Vivoactive and previous Forerunner were miles out, at least 20% under-reading. It seems to be be variable on your wrist position.

It can be if you don't cinch it up a notch or two when doing exercise, it's fine if just doing spot reads but it really needs a good firm connection with your skin when doing exercise.