I recommend buying a fitness possible watch like a Fastrack optimus 2 pro black which is cheap

Why? It cost ₹2600 inr or $27.55 as on the date of blog.

It has a heartrate tracker,an spo2 sensor,magnetic charging,oled screen,2 button(1 wheel),can connect to any Android phone provided you have the app,it can scan heartrate every 5 minutes.

Above all else:

Since it's black and has a variety of dials you can choose from on the phone +5 you can carry on the watch itself it blends itself as a top pick everydaycarry for outside the house or your comfort zone as it can be replaced rather cheaply when ticked

It also boasts a tested IP68 RATING .

I WASHED IT WITH DISH SOAP AND WATER FROM A NORMAL FLOW RATE TAP (1 LITER IN LIKE 15 SECONDS)