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Forerunner 645 vs Fenix 5

I now have the Fenix 5. I am thinking of getting this 645. I dont listen to music, do pay, no map,etc I dont golf or swim. Only do bicycling, run and walk. Is the 645 a good watch for me?
  • I just got my 645. So much lighter and thinner than Fenix 5.
  • Why would you want to replace a higher end watch like the Fenix 5 for the FR645, if you are not interested in the extra features that could offer like music or Garmin Pay?


    Clearly you are not a runner then. I can't imagine any serious athlete who would prefer to have a bulky 87 gram watch on their wrist than a 42g watch when the functionality is almost exactly the same.
  • Clearly you are not a runner then. I can't imagine any serious athlete who would prefer to have a bulky 87 gram watch on their wrist than a 42g watch when the functionality is almost exactly the same.


    I run 3 times a week! ;-) And I own a FR645M btw. There are enough reasons to prefer a Fenix 5 over a FR645, even when you are a runner (e.g. the most important one is maybe battery life using GPS when you are doing ultra runs or when you run triathlons, since the Fenix supports multi-sport activities and the FR645 does not). Also... some may find the looks of the Fenix 5 better as well, but that has nothing to do with running.
  • Former Member
    0 Former Member over 6 years ago
    Clearly you are not a runner then. I can't imagine any serious athlete who would prefer to have a bulky 87 gram watch on their wrist than a 42g watch when the functionality is almost exactly the same.


    Really? I can't imagine a "serious athlete" who choose a limited 645 over a Fenix 5 that provides all the tools and metrics a "serious athlete" need and require. Unless of course music has now become a "serious athlete" requirement. The 645 and Fenix 5 are far from being "functionally almost exactly the same".
  • I find the 645 and Fenix 5 to be the same in Walking, Running and Cycling. That is all I use it for.

    I dont know if the Altimeter, Barometer, GPS hardware, etc are the same on both.

    Functionality, there is no hot key on the 645, cant do bi/triathlon and a few other things.

    It has LIveTrack / Grouptrack map and this is what I need.
  • Really? I can't imagine a "serious athlete" who choose a limited 645 over a Fenix 5 that provides all the tools and metrics a "serious athlete" need and require. Unless of course music has now become a "serious athlete" requirement. The 645 and Fenix 5 are far from being "functionally almost exactly the same".

    Fenix 5 and FR645 are not that much different looking at functionality if you are a runner only. And if you are really a “serious athlete” you would choose a FR935! ;-) The material and reduced weight compared to a Fenix 5 make GPS and OHR better and a better sports watch in my opinion. I think the FR935 is also still DCR’s favorite watch. :-)
  • Former Member
    0 Former Member over 6 years ago
    chong67 Yes, if you didn't used the Fenix 5 to it's full capabilities and you used it the same way as the 645, you would see them as equal. This is perfectly fine. I know there are dedicated athletes who use the 645. There are also people who workout here and there that own a Fenix 5. This I'm sure is due to personal preference on looks, cost, etc. When you are considering someone as a "serious athlete" you think of someone who knows the importance of the numerous metrics that the Fenix 5 has that the 645 doesn't. Just take a look on Garmin's homepage and compare the two. The Fenix 5 actually weighs 85 grams and the 645M 42.2. Taking cosmetics, price, etc. out of the equation, I find it extremely hard to believe the deciding factor for a "serious athlete" would be 42.8 grams. It's more probable a "serious athlete" is going to choose a device that's going to provide them the data they can better train and compete.
  • Former Member
    0 Former Member over 6 years ago
    pcraenme Agreed a more serious athlete would be better off with a 935. My comment was based on a serious athlete using a Fenix 5 as opposed to the 645. I still believe between those two devices, the choice is obvious. As far as running only, I agree they're similar. Maybe I misunderstood Scott, but I believe there's a difference between a serious runner and a serious athlete.
  • Really? I can't imagine a "serious athlete" who choose a limited 645 over a Fenix 5 that provides all the tools and metrics a "serious athlete" need and require. Unless of course music has now become a "serious athlete" requirement. The 645 and Fenix 5 are far from being "functionally almost exactly the same".


    I disagree. The serious athlete just wants a comfortable, lightweight and accurate GPS watch. The Fenix 5, in my opinion, falls short in these key areas. Stainless steel degrades the GPS signal (there are plenty of threads on here to prove this) and simply makes the watch too heavy for competitive running, in my opinion. It might look prettier, but serious athletes don't care - they are more bothered about real time pace accuracy than aesthetics.

    If you are a big guy who plods around a marathon in 5 hours then maybe the 87g weight of your watch is irrelevant, but for a skinny 5k runner doing sub 6 minute miles, they would probably prefer to wear a 42g watch.

    And battery life on the 645 is up to 14 hours (with music off), which is more than enough for even the longest of training runs. As for triathlons, if you regularly do triathlons or Ironmans then clearly the 935 is the better watch for you.
  • scotthunter2 then it seems to me the choice should be between 645 and 935 - whether music is more important than the extra battery life and other features of the 935