Xiaomi - Mi Band 2

Some are kinda decent if you just want a basic fitness band with notifications and music controls. There are some decent brands that make them, like Haylou, Xiaomi, Amazfit, etc. However, what I see with these more basic smartwatches (had experience with Miband), is that their notifications capabilities are much less robust than WearOS. That was the primary reason why I upgraded from Mibands to a Galaxy Watch.

Do you want to just measure distance and track your route and heartbeat? If so the cheeapest is to get a smart band (i have the MI smart band). I can't remember the price but it's definitely less than 100, but obviously will not have as many things as a sport watch like the others suggested. It can also be a good idea to get something cheap and if in a couple years you still use you can save for something better

I've used "Mi Bands" (Xiaomi Smart Band) for the longest time, fundamentally for Step Counting and Sleep Tracking, rarely as a bluetooth remote control and for NFC payment. It's very small and unintrusive, doesn't bother you at all and it only needs charging every two-three weeks. You don't have to use all the unneccesary bells and whistles obviously.

I tried the MiBand. I found it very inaccurate so I ended up not using it