The Polar integration into Home Assistant currently does not seem to work:

https://github.com/burnnat/ha-polar/issues/16

but the Strava Integration does work:

https://github.com/woolf0007/ha_strava

Strava has a Community in the Home Assistant forum:

https://www.google.com/search?as_q=home+assistant+strava&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=&as_occt=any&safe=images&as_filetype=&tbs=