I’m helping a friend choose a wearable health monitor. We are simply going by lists of features such as HRV, body battery, sleep quality, blood oxygen levels, etc. But I’ve read that some of these features are so unreliable that they are best ignored.

So my question is, in our list of features, are there any we should ignore?

They want to monitor as much as possible. They’re in very good health: a nutritionist who meditates, practises psychotherapy, runs twice weekly and does kettle bells twice weekly.

I’m lending them my Garmin Vivoactive 5. It does quite a bit already, although I find the apps around these things so tedious that I’ll probably stop using them personally.