My heart rate monitor arrived last night. I got a Polar H10. I love the experience of measuring my heart rate. I love it because it straps around my chest, it's invisible, and the data is easy to read and export. Not only that, but the battery supposedly lasts for 400hrs, it can connect to your iPhone or any other fitness tracking apps (like Strava), and it comes with an app, the Polar Flow app, where it makes it super easy to record new sessions.

I was able to export a 5min log of my heart rate. It comes with a bpm value for each second during the session.

That's very close to how I want to be able to export my emotional data in the future.