Garmin Forerunner Buying Guide

Garmin is a leader in making GPS sports and fitness watches and there are several models to choose from.  Your budget may determine in large part which watch you choose but so should your needs.  In this buying guide, I’m focusing on Garmin’s running watches because it can be a little confusing what the difference are between each and whether it’s worth spending more or not, depending upon your specific needs and budget.

I’ll be creating a guide for Garmin’s multi-sport/hiking watches too but this one focuses on running watches, although some of them support multi-sports and hiking!  Yeah, it can be confusing.

Garmin Running Watches Feature Comparisons

If you’re a runner than Garmin is going to have plenty of choices for you to choose from.  Some watches are dedicated running watches and others are multi-sport but also support running as an activity.

The Forerunner® line-up is of course Garmin’s answer for hardcore runners and there’s several products to choose from.

Garmin Forerunner® 35

Forerunner 35 in Black
Forerunner 35 in Black

I happen to think that this is one of the best looking watches Garmin makes.  The Forerunner® 35 (View current price on Amazon) is lightweight and no-nonsense but it still has the features needed for GPS-based running and walking.  This is a great entry-level running watch.


Product Highlights:

  • Built-In GPS
  • Heart rate sensor with heart rate zones and VO2 Max
  • 5ATM Water Rating (it can get wet and you don’t have to worry about it)
  • Supports ANT+ devices (chest HR straps, foot pods, etc)
  • Running Modes
    • Free – outdoor or indoor running at your own pace (indoor is without GPS on)
    • Run/Walk – for running and walking intervals
    • Virtual Pacer® – Run against a virtual partner
    • Intervals – for interval-based workouts based on distance or time
  • Auto Laps
  • Cadence (steps per minute)
  • Also supports cycling
  • Smart notifications
  • Music controls (no music storage)
  • Alarm Clock / Stopwatch / Weather / Find my Phone
  • Sleep Tracking

Forerunner 35® Specs:

  • Chemically strengthened glass lens
  • Silicone strap
  • 37.3 grams
  • Physical size 35.5 x 40.7 x 13.3 mm
  • Transflective display for great outdoor readability
  • Battery life up to 9 days in smartwatch mode and 13 hours for continuous GPS usage
Why Choose the Forerunner® 35? 

Obviously, as one of the most affordable Forerunner watches, it’s attractive because of its’ price but it’s also an easy to use, nice looking, lightweight GPS watch ideal for walking, running and cycling.


Forerunner® 235

Forerunner 235 Color Options
Forerunner 235 Color Options

The Forerunner® 235 (View current price on Amazon) is a step-up from the Forerunner 35 in that it supports downloading watch faces, widgets, and apps from the Garmin Connect IQ™ store.  It also supports GPS + GLONASS for improved tracking, a color display, and customizable data pages and activity profiles.  The Forerunner 235® also has the handy back to start feature to help navigate you back to where your began your activity.

Product Highlights

  • Built-In GPS+GLONASS
  • 24/7 Heart Rate Monitoring, HR Zones, VO2 Max, Aerobic Training Effect
  • Connect IQ Store (for downloading watch faces, widgets, apps)
  • 5 ATM Water Rating
  • Supports ANT+ (Heart rate sensors, foot pods, etc)
  • Running Modes
    • Free – outdoor or indoor running at your own pace (indoor is without GPS on)
    • Run/Walk – for running and walking intervals
    • Virtual Pacer® – Run against a virtual partner
    • Intervals – for interval-based workouts based on distance or time
  • Auto Laps/ Manual Laps
  • Cadence (steps per minute)
  • Supports Cycling
  • Smart Notifications
  • Music Controls (no music storage)
  • Alarm Clock / Stopwatch / Weather / Find my Phone / VIRB® Camera Remote
  • Sleep Tracking

Forerunner 235 Specs:

  • Chemically strengthened glass lens
  • Silicone strap
  • 42 grams
  • Physical Size: 45 x 45 x 11.7 mm
  • Transflective color display for outdoor readability
  • Battery life up to 9 days smartwatch mode and 11 hours GPS mode
Why Choose the Forerunner® 235?

The Forerunner 235 is a step up from the Forerunner 35 in that it has a color transflective display and GPS+GLONASS which may provide more accurate GPS readings.  This watch is best for running and cycling.


Garmin Forerunner 645 Music

Forerunner 645M Family

The Forerunner® 645 Music (View Current Price on Amazon) is the first Garmin watch to support music storage on the watch itself, so you don’t need to bring your phone along in the gym or on your outdoor activities to listen to music while you work out.  This is a feature that many have been asking for.

The Forerunner 645 comes in two different versions, the Forerunner 635 which doesn’t support music storage and, you guessed it, the Forerunner 635 Music which does.  The one that supports music storage is about $50 more than the other and personally I think it’s probably worth spending the extra $50 bucks to get that feature because it’s the major appeal of the watch and what sets it apart from every other Garmin, so far anyway.

I’m assuming that we’ll see music storage on other future Garmin watches but the 645 Music is the first.

Another feature of the 645/645 Music is that it supports Garmin Pay™.  The only other Garmin watch that I know of that also supports Garmin Pay is the Vivoactive 3.  This is a feature that will probably be on all future Garmin watches above a certain price-point.

Other notable features we get as we move up the Garmin running watch food chain beginning with the 645 is a barometer for estimating altitude and a thermometer.


Product Highlights:

  • GPS + GLONASS
  • 24/7 HR Sensor
  • Training Status/ Training Effect (aerobic and anaerobic) / Training Load
  • Fitness Age Estimate
  • Pool Swimming
  • Download Training Plans
  • Multi-Sport (Strength training, cardio, elliptical, rowing indoor/outdoor, stair stepping, floor climbing, Yoga, skiining, snowboarding, XC skiing, stand up paddleboarding, biking indoor/outdoor, pool swimming, running)
  • LiveTrack™
  • Music Storage up to 500 Songs
  • Supports some streaming music services (iHeart Radio)
  • Garmin Pay™ (wireless payments for select banks)
  • Advanced Training Dynamics
  • Auto Lap™ / Manual Lap
  • VIRB® Camera Remote
  • Connect IQ™ (download watch faces, widgets, apps)
  • Sleep Tracking
Forerunner® 645 Music Specs:
  • Chemically strengthened glass lens
  • Stainless steel bezel
  • Quick release 20 mm silicone straps
  • Physical Size 42.5 X 42.5 x 13.5mm
  • 42.2 grams
  • 5 ATM
  • Transflective Color Display
  • Barometer
  • Compass
  • Gyroscope
  • Battery Life of up to 7 days smartwatch mode and 5 hours GPS mode
Why Choose the Garmin Forerunner® 645 Music?

The most obvious reason to choose the Forerunner® 645 Music is to be able to store music directly on the watch.  It is the first Garmin to have this feature.  It also supports Garmin Pay™ which is still limited in the number of banks that support it, at least at the time I’m writing this.  It’s also a multi-sport watch and has those handy quick release straps for easy changing.  Basically, you’re getting many of the newer features that Garmin has to offer.

The 645 Music compares best against the Vivoactive 3 (View price on Amazon) because both support Garmin Pay and are two of the newest watches for Garmin in 2017/2018.  The 645 Music has the edge because you can store music on it and download routes to navigate for hiking/biking etc., but of course that comes with a higher price tag.


Garmin Forerunner® 735XT

Forerunner 735XT – Black

With the Garmin Forerunner® 735XT (View current price on Amazon) you’ll be getting everything that the Forerunner® 235 has plus quite a bit more including more advanced running metrics (ground contact time, stride length, vertical ratio) pool and open water swimming, and very good cycling features.

Other activities that it tracks include indoor cycling, cross-country skiing, paddle sports, hiking, trail running, and strength training.

The 735XT also supports more advanced navigational features such as live bread crumb trails and point-to-point navigation.


Product Highlights:

  • Built-in GPS+GLONASS
  • 24/7 Heart Rate Monitoring including VO2 Max, HR Zones, HR monitoring during swimming, HRV (heart rate variability) stress test)
  • Lactate Threshold estimate / Race Predictor / Recovery Advisor
  • Multi-Sport (running indoor/outdoor, cycling indoor/outdoor, swimming pool/open water, cross country skiing, paddle sports, trail running, hiking, strength training)
  • Connect IQ Store (for downloading watch faces, widgets, apps)
  • 5 ATM Water Rating
  • Supports ANT+
  • Auto Laps / Manual Laps
  • Compatible with Strava Live Segments (2-month free trial)
  • Cadence, ground contact time, stride length, vertical ratio
  • Bread crumb, back to start, point-to-point navigation
  • Smart Notifications
  • Music Controls (No music storage)
  • Alarm clock, stop watch, weather, calendar, sunrise/sunset
  • Compass / GPS Coordinates
  • Sleep Tracking
  • LiveTrack™

Forerunner® 735XT Specs:

  • Chemically strengthened glass lens
  • Silicone strap
  • 44.5 x 44.5 x 11.9 mm
  • 40.2 grams
  • 5 ATM
  • Transflective color display
  • Battery life up to 11 days in smartwatch mode, 14 hours GPS mode
Why Choose the 735XT?

The 735XT is giving a lot of what Garmin has to offer in more expensive models.  It’s a multi-sport watch withe advanced running dynamics that connects with Garmin IQ which allows you to download watch faces, widgets, and apps.  It also has good navigational features such as a live bread crumb trail, point-to-point navigation, and back to start.  It also has a compass and can display your GPS coordinates. It also supports downloading courses.  The 735XT also supports both pool and open water swimming. The upside to the 735XT is the price for the features while downside to the 735XT is the build quality.  The build quality isn’t as good as the more expensive 935 or Fenix 5/5X/5s so if you want a more durable watch you might want/need to spend more.


Forerunner® 935

Forerunner 935 – Amp Yellow and Black Options

The Garmin Forerunner 935 (View Current Price on Amazon) is the most expensive of Garmin’s running watches and it’s very similar to the Fenix 5/5X/5s.  This is a watch that can be used for triathlons and supports advanced dynamics for running, bicycing, and swimming.  It also has the longest battery life of all the watches on this list with a battery life of up to 2 weeks in watch mode and 24 hours in GPS mode.  You can squeak out 50 hours in UltraTrac™ Mode but the performance will likely suffer.

The 935 also supports downloading courses to the watch to be used for hiking or running or most GPS activities.

You also get point-to-point navigation, TracBack®, elevation, barometric trends with storm alerts, area calculator, hunt and fish calendar, sun and moon info, and many other features.


Product Highlights:

  • Built-in GPS + GLONASS
  • 24/7 HR Monitoring, VO2 Max, HR Zones, Recovery Time, HRV Stress Text (with compatible HRM chest straps)
  • Advanced dynamics for running (cadence, stride length, ground contact time and balance, vertical oscillation and vertical ratio)
  • 5 ATM for Swimming
  • Triathlon / Auto Multi-Sport
  • Pool Swimming / Open Water Swimming
  • Connect IQ™ Store (watch faces, apps, widgets)
  • Music Controls (No music storage)
  • LiveTrack™
  • Fitness Age Estimate
  • Smart Notifications
  • Calendar, weather, compass, barometer for storm alerts
  • Point-to-Point Navigation / Bread crumb trails / TracBack® / Elevation Profiles / Total Ascent / Total Descent / Sight ‘N Go / Area Calculator / Hunt & Fish Calendar / Sun & Moon Information
  • Alarm clock / timer / stopwatch / sunrise & sunset
  • Supports Golf
  • Supports Courses (routes created or downloaded for hiking, cycle, running etc.)
  • Sleep Tracking
  • and More!

Garmin 935 Specs:

  • Chemically strengthened glass lens
  • Fiber-reinforced polymer bezel
  • Fiber-reinforced polymer case
  • QuickFit™ 22 mm silicone straps
  • 49 grams
  • Physical size:  47 x 47 x 13.9 mm
  • 5 ATM
  • Transflective Color Display
  • Barometric Altimeter
  • Compass
  • Gyroscope
  • Accelerometer
  • Thermometer
  • Battery life up to 2 weeks watch mode and 24 hours GPS mode
Why Choose the Garmin Forerunner® 935?

The Forerunner® 935 is very similar to the Garmin Fenix 5/5X/5s (View prices and options for the Fenix on Amazon) so you’ll be getting tons of features and advanced metrics.  The main difference between the 935 and the more expensive Fenix is the build quality of the watch.  The 935 features a lightweight plastic body.  It’s a good quality plastic though. The body of the Fenix is composed of stainless steel.  The Fenix is also is available in three different sizes: 42 mm for the 5s, 47 mm for the standard Fenix 5, and 51 mm for the Fenix 5X. The 5X supports downloading topographical maps, so if you’re doing some serious hiking it might be the one to choose, although it’s a big watch.  I personally have the 5s which is ideal for smaller wrists and everyday wear.  The 935 is 47 mm in diameter so still a large watch but more lightweight than the Fenix 5 47 mm version.

The Fenix also has a 10 ATM water rating compared to the 935’s 5 ATM rating, so if you do lots of swimming, especially in deeper water, you’ll probably want to go with the Fenix.  The bottom line is that the 935 is a great option if you want to save some money and get pretty much the same features as the Fenix.