Garmin
Forerunner 255 Series
Long battery; but wrist HR tracking is inconsistent.

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You could look at an instinct 2S or a Garmin instinct E, both are 40mm
Honestly your best bet would be a Venu or an instinct, Venu is Garmin's health and fitness while instinct is there more traditional "G-Shock" style (best way I can describe it) watch, they don't really do the fitness tracker it's mostly all smartwatches. I have the Venu 4 coming from an instinct 2 solar. The vivo moves might also fit you well but they are older in comparison. If you are set on not having a smartwatch you may have to look into another brand, hope this helps, if you have any questions about the Venu or instinct let me know!
I would go for either the Instinct 3 or Vivoactive 6. Both new watches are great, no issues. Vivoactive 6 is just in your budget range but isn't very 'rugged', which is the perfect desciption of the instinct 3 (which is a bit more pricey). You can go for the black and white screen of the Instinct E ($299), but the tech is a bit more dated, and if you are coming from an apple watch, im guessing you like the bright screens. Another option is the Epix 2 (refurbished) from amazon for $349 (what I would go for). This is their top of the line watch from a few years ago, but still very advanced with most of the new features. [https://www.garmin.com/en-US/p/1316397/pn/010-02936-00/](https://www.garmin.com/en-US/p/1316397/pn/010-02936-00/) [https://www.garmin.com/en-US/p/1555457/](https://www.garmin.com/en-US/p/1555457/) [https://a.co/d/fs1SPqL](https://a.co/d/fs1SPqL)
My Instinct 2s (40mm - non solar) is the perfect smartwatch to me. Perfect size, perfect feature set, nice color (Surf Edition), nice extensibility (Connect IQ). Just that I would really like a better battery life. Currently I charge it around once per week and there will be a time in the future where I need to replace the watch when the battery has degraded more. I'd really like to keep the small size, but there's only the Instinct E available which has an even lower battery life than the 2s. Preferably, I'd like to have solar charging, but the I3 Solar is only available in 45mm and 50mm. And even the 45mm I find already too large for me personally. So I'm really at a loss when thinking about what might be my next watch after this Instinct 2s. I even thought about simply going back to a G-Shock, but I would miss quite a few features of my Instinct then, so this is also not a real solution.
You are not vastly overweight, but smart to get in shape Re: recommendation- so many options between $120 (vivosmart 5 on Amazon sometimes) and $1200+. See the Garmin website. Without knowing what your aesthetic is, I would guess either Venu 4 or Instinct E. You get a lot of value from an Instinct E, if you like the looks. Venu has a different style and also suggested daily workouts for walking. Tracking the ‘training status’ on that and higher end watches is motivating too. Warning- Garmin does not make it easy to use incline % with treadmill workouts. Not sure about Apple https://www.reddit.com/r/Garmin/comments/p1oux5/is_there_a_way_to_log_treadmill_inclines/ If you are someone who is good at charging a watch every day, an Apple Watch might be better for you- Garmin is not as good for weightlifting or swimming, in my experience. Might be close call for sleep (debatable). Among iPhone users, Garmin is better for (1) people who insist on decent battery life (me) (2) training for running, biking, triathlon. Also golfers. Better GPS if you are wanting that for hiking. If you like to walk outside it is probably a wash. (3) Apple fitness might be really great in your situation, which (obvi) is way better with an Apple Watch than a Garmin
Garmin Instinct 3 solar, 50mm, or Instinct E if you are tight on budget. Works with Healthy365 and has impressive battery life. Expensive, but long lasting. (I got my first gen instinct lasted for 5 years before switching to the current Instinct3)
It depends on what you want/need. My Garmin Instinct E-Sports is still going strong and I wear it on occasion, but my “daily driver” is a fenix 7s Solar. Made the switch a few years ago because I wanted the golf elements of the 7 that the original Instinct lacked. I get 10-11 days on my fenix, but well over a month still on the Instinct. Been tempted to get an Instinct 2 Solar foe even more battery life.
Garmin
Forerunner 255 Series
Long battery; but wrist HR tracking is inconsistent.

Garmin
Forerunner 955 Series
Best value, clear MIP screen; limited smartwatch features.

Garmin
Fenix 7 Series
Durable, multi-week battery, flashlight; high price, buggy software.
Garmin
Instinct 2 Series
Rugged, solar multi-week battery; bulky, small screen readability issues.

Garmin
Enduro 3
Multi-week solar battery, lightweight; but bulky form factor.

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Oura - Oura Ring Series

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Apple - Ultra Series

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Garmin - Enduro 3

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Garmin - Fenix 7 Series

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Garmin - Forerunner 255 Series

Ranked #1
Oura - Oura Ring Series