That should be relatively easy. Battery could be a problem, but you can use https://espruino.github.io/BangleApps/?id=hrmaccevents to test this. It can stream accelerometer and pulse data as fast as possible. If you can do that for a day there should not be major problems for your usecase.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
That should be relatively easy. Battery could be a problem, but you can use https://espruino.github.io/BangleApps/?id=hrmaccevents to test this. It can stream accelerometer and pulse data as fast as possible. If you can do that for a day there should not be major problems for your usecase.