VO2 max intervals

Garmin watch is not useful for vo2 max intervals. It is way off for heart rates above 160 or so. This is my observation and many others report the same.

I only just a Garmin Dual strap now. I used to dual record with an Apple Watch to enable simultaneous use various different apps. Although I never drilled down into a minute by minute comparison, my understanding is that the sampling rates were different. Are a few beats difference a significant factor when measuring performance?

How is it off? I use a heart strap monitor which I think is pretty accurate? Can you give an example please as this is important to know when doing VO2 max training. Thank you.

I beleive He’s referring to the Garmin Watch’s Built In Optical HR sensor. My experience in using it is also similar, it is dreadful when there is a lot of arm swinging.

I only use a Chest HR (PolarH10) tho I am toying with the idea of a bicep/arm based optical HR as I tend to get chaffing using the chest strap.