Best Fitness Tracker, Expert Advice to Choose

I am looking for the best fitness tracker as my doctor advised me to start monitoring my daily activity because my energy levels have been dropping lately. i have been experiencing inconsistent sleep and trouble keeping track of my steps, workouts, and heart rate. i went through reviews from trusted sources like CNET, Wirecutter, and Android Authority and after comparing many options these two kept coming up as the top choices:

WHOOP 5.0/MG Activity Tracker

Garmin vívoactive® 6, Health and Fitness GPS Smartwatch

however, i am having trouble deciding which one would be better for me and i would love to get your expert advice and hoping maybe some fitness trainers, health-tracking enthusiasts, or anyone experienced with different wearables on this forum can also share their advice. i usually go for morning walks and light workouts, but i also want something that helps me stay consistent and keeps me motivated. would either of these be recommended for me? Any suggestions or advice would be appreciated.

Thanks in advance

If you have an Apple Watch you own something that does all these.

You will probably receive more plentiful and helpful replies if you post this on Facebook or Reddit in a page specifically discussing this question. I’ve seen this same question on Reddit with many helpful replies and discussions. Just do a search for ‘fitness tracker’ on the main Reddit search bar. You’ll find numerous posts about it. Good luck in your search!