Privacy Friendly Fitness Trackers

I am trying to find a privacy friendly fitness tracker. Mainly need it for heart rate monitoring, and swimming, so I do not need all the bells and whistles although extra fitness/ health applications would be nice. I am mainly trying to find something that does not require a phone app (or if it does then a privacy friendly one that work work with grapheneOS), something that does not require Bluetooth, location, or internet connection to work. Would love to …

fitness privacy