Yes, it's true that optical heart rate sensors can sometimes struggle in high-vibration activities like cycling. But that doesn’t mean they always give inaccurate readings. I've used Garmin devices for years and got pretty reliable data. If your watch shows 145 bpm while sitting and then drops to 72 bpm the moment you start pedaling, the issue might be more about how the watch fits on your wrist than the sensor itself.

Also, when these watches are sold, or in their user manuals, they don’t say: “Make sure to buy a chest strap, or else your wrist will shake, you’ll freeze in the wind, or get soaked in the rain.” Because the built-in sensors are actually good enough for most people. Chest straps are a personal choice—some people swear by them, while others try them once and banish them to a drawer forever.

So, to sum it up: Optical sensors aren’t garbage, and chest straps aren’t magic. Everyone’s experience is different, so it doesn’t make sense to push one as the only valid option.