Fitness Tracker Watch

I've never had any fitness tracker watch before so I don't know what I'm really looking for. I have a Samsung s21, I'm not having any apple watch. My budget is low, at a maximum maybe £70 so I know it's not going to be able to do everything but what's the best I can get for that money?

I've seen so

Went to a festival and had a very elevated heart rate for a prolonged period of time, due to stimulants (and dancing / walking around I guess). My fitness tracker watch said I burned something crazy like 8000 kcals each day.

If your heart rate is artificially elevated by substances, then are you b

I'm trying to recover from a chronic health condition called POTS, and I need to find and record a heart rate zone where I can do laps without triggering my nervous system into major hyperarousal. So I'm trying to find a watch that shows accurate readings. I know with these watches you can't expect

I'm trying to find a fitness tracker watch that will track heart rate, so I can track my symptoms more accurately, but I don't want one that shows notifications from my phone--I'm already addicted enough to my phone and I'm trying to decrease the amount of time I spend with it. Any recommendations?

My old automatic watch finally broke and I've been looking around for a replacement watch / fitness tracker but I haven't found a product that has everything I'm looking for. My main requirements is it has to function as my watch (always on time/date display and reasonably stylish). Additionally, th