I am interested in being able to use a smart watch to do sports, I don't care if it has integrated GPS since when I go running I carry my phone and I don't need GPS to go to the gym.
I have looked at two viable options 1) use opentracks (an open source application that records sports) I think opentracks can be used together with sports bands that measure heart rate such as the polar H10 (the bad thing about open tracks is that there does not seem to be a big team of developers behind it, I think there is only one person) and I cannot synchronize the data with that of my Withings smart scale
On the other hand, I have seen this page on reddit where it is discussed whether the firmware could be changed for Withings products, if that were the case it would be the best option (Someone with knowledge of this topic can add information to the page).
https://www.reddit.com/r/withings/s/3csDWv2UJf