Video Reviews on YouTube
Visit me on Instagram
Follow me on Strava
Visit me on Facebook
RSS Feed
Visit me on Twitter
Share by Email
Visit me on Google+

Garmin Forerunner 645 Review

  • Editor Rating
  • Rated 5 stars
£349 to £399
  • 100%

  • Garmin Forerunner 645
  • Reviewed by:
  • Published on:
  • Last modified: 15th May 2018
  • Heart Rate functionality
    Editor: 98%
  • Heart Rate Accuracy
    Editor: 98%
  • Activity Tracking features
    Editor: 100%
  • Running functions
    Editor: 100%
  • Cycling functions
    Editor: 90%
  • Fitness monitoring features
    Editor: 100%
  • Ease of Use
    Editor: 100%
  • Battery Life
    Editor: 100%

Finally …. we have a Garmin Forerunner watch with BUILT-IN music store and a replacement to the superb Forerunner 235? This new Garmin Forerunner 645 watch looks certain to be the replacement to the hugely popular Forerunner 235. This review of the Garmin Forerunner 645 has been brought to you by Tristan Haskins aka CardioCritic

Released > January 2018

Replaced > Garmin Forerunner 235

Suggested Retail price (at time of release) > £349 to £399 / $399 to $449 (with or without music)

Who’s It For?

The Garmin Forerunner 645 is perfect for 95% of serious athletes, fitness enthusiasts, runners and anyone else looking to take their training to the next level. It’s packed with Fitness Tracking features such as 7 Day Training Load, 4 week Training Status and VO2 Max. Other great features include contactless payments and an internal memory to store over 500 songs …

I personally use the Garmin Fenix 5 as my daily training watch. I am hoping they might find a way of adding the Forerunner 645’s internal music store and contactless payments to the Fenix 5. There’s not many features I’d miss by switching down to the Forerunner 645.

Key functions MISSING from the Forerunner 645 PRESENT in the Forerunner 935 and Fenix 5 are:

  • No multisport support – eg Triathlon or Duathlon mode
  • Support for Power Meters (cycling)
  • FTP (cycling power related performance metric)
  • Open Water swimming metrics
  • Lactate Threshold prediction
  • Golf courses

A full ist of differences can be found here at (compare Forerunner 645, Forerunner 935 & Fenix 5)

In short, if you don’t play golf, are NOT interested in power metrics (cycling) and don’t partake in multisport events like duathlon and triathlon – the Garmin Forerunner 645 is for you …

Memory for 500 songs

Transfer music directly from your computer and add it to your playlist. To listen to the music you need a pair of Bluetooth headphones – we recommend for value for money the JBL Reflect as shown below. A full list of compatible Bluetooth headphones is provided on Garmin’s support pages. With the Forerunner 645 it’s now possible to listen while you train – FREE from your smartphone. For Premium subscriber’s to the Deezer platform – you can synchronise your playlists directly to the 645 ad free.

Garmin Contactless Payment

Other key new features added to the Forerunner 645 are Garmin’s contactless Payment System. Garmin Pay Ready contactless payment method lets you make convenient payments with your watch, so you can leave your cash and cards at home

Battery Life

  • Smartwatch Mode: Up to 7 days
  • GPS mode without music: Up to 14 hours
  • GPS mode with music: Up to 5 hours

Clean, stylish lines

We loved the Garmin Forerunner 235 – one of the best GPS running watches of the last 5 years. But there’s no getting away from the fact that it was a bit “plastic” looking. The new Garmin Forerunner 645 has similar lines to the Vivoactive 3 with stainless steel bezel and Gorilla Glass 3 adding to the quality look and feel

Garmin Training Status

I have been using the Garmin Fenix 5 for the last 4 weeks and Training Status is the BEST serious fitness innovation since built-in heart rate monitoring. No more guessing if you’re under trained or over trained. The Garmin Forerunner 645 will tell you precisely what your personal training status is.

Videos (Garmin Marketing)

External References is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon properties including, but not limited to,,,,, or Likewise, we are members of other private affiliate programs and may earn comissions on purchases done by referrals at no additional cost for the buyer.