Garmin Forerunner 935

Garmin Forerunner 935
  • Editor Rating
  • Rated 5 stars
£499 to £559
  • 100%

  • Garmin Forerunner 935
  • Reviewed by:
  • Published on:
  • Last modified: 19th June 2017
  • Heart Rate functionality
    Editor: 100%
  • Heart Rate Accuracy
    Editor: 98%
  • Activity Tracking features
    Editor: 100%
  • Running functions
    Editor: 100%
  • Cycling functions
    Editor: 100%
  • Fitness monitoring features
    Editor: 100%
  • Ease of Use
    Editor: 95%
  • Battery Life
    Editor: 100%


The Garmin Forerunner 935 was released in April 2017. If you have been trying to decide between the Garmin Fenix 5 and the Forerunner 735XT fear not … the Garmin Forerunner 935 has arrived. Like the majority of Garmin’s top end sports watches it features wrist based heart rate monitor and built in GPS. Add to that a barometric pressure sensor and digital compass. The Forerunner 935 is suitable for all elite athletes from Triathlete to Adventure Racer. This review of the Garmin Fenix 5 has been brought to you by Tristan Haskins aka CardioCritic

Release Date (UK) > April 2017

Product it replaced > None – the 935 is a new product

Suggested Retail Price (when new) > £469

Who’s It For?

The Garmin Forerunner 935 is for any serious athlete who runs, bikes, swims .. whatever. It’s perfect for outdoor adventure racers, fell runners, triathletes, elite runners, skiers, snowboarders and mountain climbers. Not only it is a firm favourite as 2017’s best running watch, but also as the best new watch for triathletes of 2017. It has the most comprehensive array of performance monitoring features on any GPS sports watch. If you have been considering a Fenix 3HR or Fenix 5 but don’t need the route follow then the 935 could be for you. (note > for winter sports it even features ski lift versus downhill time detection & data)

Wrist Based HR

The Forerunner 935 has the convenience of heart rate without the need of a chest strap with all day activity and heart rate tracking.  For elite athletes there are many advanced training metrics such as VO2 Max, Running Dynamics and Recovery Prediction.

The Perfect watch for Triathlon

The Forerunner 935 features genuine multisport functionality making it perfect for triathletes. The Forerunner 935 can switch between SWIM > BIKE > RUN modes at the press of a button. The Forerunner 735XT is still a highly recommended triathlon watch but the 935 adds new training features including Training Status and a 7 day rolling Training Load indicator to prevent over-training. 

Which Forerunner for you?

Confused by all the Forerunner watches? Don’t be. The Garmin Forerunner range of GPS sports watches is extensive with over a dozen models in the last 10 years. I’ve produced a short history of the Garmin Forerunner to help you get the latest and most appropriate Forerunner watch for your needs and budget.

Next Model Up

The only model superior to this Forerunner 935 is the beautiful but bomb proof Garmin Fenix 3 HR and Fenix 5. Almost identical functionality with wrist based heart rate, GPS and barometric pressure sensor. The main difference is the Waypoint navigation and optional Sapphire glass found on the Fenix range. The Fenix range are the ultimate outdoor GPS sports watches for adventure racers and anyone who wants a watch that can stand up to pretty much anything. The newer Fenix 5 also offers wrist based heart rate monitor and has the bonus of availability in 3 x different case sizes.

Garmin fenix 3 HR

Garmin fenix 5

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Pros

  • Technique Analysis with advanced Running Dynamics
  • Triathlon mode > Swim to Bike to Run with transition times
  • Barometric Pressure Sensor
  • Training Progress - tells you if you are improving
  • Training Effect - live feedback warning if you are training too hard
  • Training Status - evaluation of the last 7days of training
  • Up to 24hrs battery life in GPS mode
  • Up to 60hrs in UltraTrac battery saver mode
  • 2 weeks charge when using as a day-to-day smartwatch
  • Compatible with smartphone and push notifications
  • Activity Tracking including Floors Climbed
  • GPS+ GLONASS
  • The perfect all round sports watch
  • Compatible with Strava Live Segments
  • Cons

  • What can I say ..... nothing ...
  • Next Model Down

    The model directly below this Forerunner 935 is Garmin Forerunner 735XT. It has all the multisport functionality of the 935 but none of the Outdoor Recreation features. The Forerunner 935 offers these outdoor features thanks to it’s barometric pressure sensor. The sensitive altitude monitor gives access to vertical climb feedback, elevation profile and other ascent/descent metrics. Also, the 935 comes equipped with even more advanced over-training prevention tools like the 7 day Training Load analysis. The bottom line here is … if you can afford the Garmin Forerunner 935 … buy one !

    Garmin Forerunner 735XT

    Closest Competitor

    The product from competitors with the closest functionality to this 935 would be the Suunto Spartan Sport Wrist HR. Like this one the Suunto offers true multisport functionality with multiple disciplines being recorded in one exercise file. Each has it’s own pros and cons over the others and we would, in all honesty, I’d be happy having to use either for the next 18 months. Note – at time of writing this the Suunto Spartan ULTRA Wrist HR had not been released … that should also be considered as an alternative ….

    Suunto Spartan Sport Wrist HR

    Sports Monitoring to the next level

    The customer who buys a Forerunner 935 is a dedicated athlete. Someone who knows where they want to be in the next 6 months with races planned and personal records to beat. Having access to extensive training data metrics is all very well and good but an athlete needs to knwo what to do with all that data. That’s where the Forerunner 935 becomes your best friend and coach. Three of the key features found in the 935 that provide a clear insight in to your training intensity are:

    • Training Effect
    • Training Load
    • Training Status

    Training Effect

    All the best heart rate monitors I have used since the Suunto T6 have included a measure of EPOC and Training Effect. Initially devised by Firstbeat Technologies (ext link). EPOC stands for Excess Post-exercise Oxygen Consumption. In simple lay terms EPOC is the increased amount of exercise your body needs after exercise to return to normal levels (called homeostatis). EPOC, measured in ml/kg is only accurately measured in the lab with blood tests. After many years working with elite athletes First Beat have developed complex algorithms that determine EPOC from heart rate variability analysis.  To make it easier to understand Garmin use a scale of 1 – 5 to represent different levels of EPOC. This scale is referred to a Training Effect – 1 being a very low, non-productive session and 5 being a highly demanding almost over-reaching session. 

    The video below was published by Garmin on Apr 11, 2017. It gives a clear explanation of the correlation between EPOC and advanced Training Effect with aerobic versus anaerobic balance. “Aerobic training effect and the all-new anerobic training effect feature are physiological measurements designed to help you assess the expected benefits your exercise will provide. These metrics are available on select Garmin devices, giving you the tools to work toward a fitter and faster you.”

    Anaerobic versus Aerobic Training Effect

    Traijing Effect with aerobic versus anaerobic split

    Understanding which system you are training can be critical to achieving your training goals. It is possible to run 5 miles with an average HR of 60% MaxHR in many different ways. One session could be a simple recovery run with the entire session kept around 60% of MaxHR. Such a training session would have a low to moderate training effect in the AEROBIC zone. Another session could be 5 x 1 miles at RACE PACE around 80-85% of MaxHR with a heart rate based recovery to 50% of MaxHR. Such a training session would have a demanding training effect mainly in the ANAEROBIC zone with some in the Aerobic threshold. The Garmin Forerunner 935 splits Training Effect in to AEROBIC and ANAEROBIC Training Effect to help an athlete train in the correct zones according to their goals.

    Training Load

    Knowing the Training Effect from one session to the next is very useful, however, the bigger picture needs reviewing to prevent over training. That’s what Training Load comes in. Garmin Training Load is a 3 zoned summary of the last 7 day’s cumulative Training Effect. The 3 zones of Training Load are

    3 Zones of Training Load - showing Optimal from last 7 days

    • High – Be careful, your training load may be too high to produce positive results. Taking in to consideration your current fitness level and recent training habits you may be over-reaching.
    • Optimal – Maintain this level of work load. This training load is ideal for maintaining / improving your fitness
    • Low – Pick it Up ! If you continue to train at this level it is unlikely you will see any improvement in your fitness levels.

    Training Status

    Anyone who has followed a 16 week marathon training plan, or similar, will be familiar with base building, improving and tapering phases. Different websites / authors call them different things. Essentially they describe the different stages an athlete will find themselves throughout a structured training plan. – Like Training Effect and Training Load the Training Status measurement has been provided by Firstbeat. It’s another complex algorithm that utilizes many aspects of your personal physiology and recent training history.

    Forerunner 935 showing a PRODUCTIVE Training Status

    Once your Forerunner 935 has built up a short history of training sessions (about 2 to 3 weeks) it will assign one of the following Training Status to describe your current position in a structured training programme :

    • Peaking – This would be equivalent to a taper stage. It suggests you are in ideal race condition! This state is normally achieved following a short decrease in training load a week or two before a race.
    • Productive – This state suggests your fitness is improving. At this point be certain to include some REST/RECOVERY periods to keep away from over-reaching.
    • Maintaining – This state suggests your recent training loads will maintain your current fitness level. This is a good level to be at when outside competition or during base building stages
    • Recovery – You are undertaking a period of lower than normal training load. Your body is in recovery and you should be able to return to higher load when you feel fit and strong enough to do so.
    • Unproductive – Eeeeks … are you under the weather, maybe suffering with a cold … This state suggests your current training load is good, however, you actual fitness level is DECREASING. Take some time out to review diet, general health, sleep, nutrition etc.
    • Detraining – It could be time to increase training load. You’ve been training much less than usual for a week or more, and it’s affecting your fitness.
    • Overreaching – This is one of the key warning zones. Your recent training loads have been successively too high and has become counterproductive. In short, listen to your body and take a rest. Spend some time performing low intensity active recovery.
    • No Status – keep training. Your Forerunner 935 needs to see two or three solid weeks of training to access VO2 Max and current Training Status

    This video published by Garmin on Apr 11, 2017 explains training status –  “Garmin is introducing a new metric called training status. Training status analyzes your data in order to tell you how your body is responding to the current training load. This lets you tailor your training to the optimal level for maximum effect.”

    More Key features

    Other great technical features found in the Forerunner 935 GPS sports watch are, Race Predictor, VO2 Max, Advanced Running Dynamics and Recovery Analysis discussed in more detail below.

    Race Predictor

    Once your 935 has analysed your VO2 Max and sampled data from your training sessions it can predict your finishing time for races of 5K, 10K, Half Marathon an full Marathon distance. As your fitness improves this times will reflect this by dropping.

    VO2 Max

    VO2 Max is a term used to describe a person’s efficiency at getting oxygen in to the body, transporting it around the body then utilising it during aerobic processes by the muscles. In reality measuring a person’s actual VO2 Max is a laboratory based test involving blood tests, a treadmill and a machine to analyse oxygen levels from your lungs. Garmin have made is easy with their VO2 Max feature. This dynamic metric can be accessed at any time. The higher the number, the fitter you are. It’s an easy, convenient and reliable method of monitoring progression

    Recovery Time

    At the end of every session your Forerunner 935 will conveniently present you with a predicted recovery time. Anything from a couple of hours up to 4 days. Recovery plays a critical part in every training programme.

    Running Dynamics

    Garmin’s Running Dynamics are for the dedicated elite runner. Everything is measured from Ground Contact time and leg Cadence to Vertical Ratio and Vertical Oscillation. Vertical Ratio, for example, reflects your running efficiency. Using Vertical Oscillation and stride length it looks at how well you propel yourself forward with each strides. In other words, whether you are bouncing too much or running smoothly and efficiently.

    Forerunner 935 Marketing Video

    This promotional video from Garmin was published on YouTube Mar 29, 2017 “If beating yesterday is your goal, Forerunner 935 is your watch. This premium GPS running/triathlon watch is designed to go the distance. Just like you.”

    In Conclusion

    The level of R&D that Garmin put in to their Forerunner range is immense. They have been making GPS sports watches for nearly 20 years and they have access to some of the worlds greatest athletes from all disciplines. Their continued work with Firstbeat developing Training Status, Training Load and Training Effect give athletes a good chance of arriving to the start line – READY to RACE. All this experience and feedback gives them a huge advantage over some of their competitors (Polar being the only others with a similar level of Training Load analysis). The Garmin Forerunner 935 gets another 5/5 Star Review from CardioCritic. There is nothing to criticize in this perfect GPS sports watch …

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