Has anyone used a Garmin to help them with pacing?

I keep getting ad's for Visible, but it only does heart rate monitoring, and has an ongoing subscription. It seems very expensive for what it does. I was looking into the Garmin, they have a 'Body Battery' which sounds useful, at least if it regularly updates as I do activities throughout the day. Has anyone used this and found it useful, or any other smart device that has a similar indicator of your physical state like this? I'd be interested in anything you have found that works.

I woke up yesterday and was feeling a bit low energy, not great, but I didn't think I was too bad, I decided to vacuum my house, did most of it, not hugely strenuous, and then ended up feeling really ill, super shaky, heart rate flying, very weak and it lasted for over 20mins of purely lying down before I started to feel better again. A device that could have told me I wasn't up to it, would have been useful.