Polar RS400sd – Heart Rate Monitor Review

Polar RS400sd Review – by John Morris

I’ve been a keen cyclist for some time now and was thrilled to be given an opportunity to review this product. I’m a beginner Triathlete and reviewing the Polar RS400sd has helped me on my journey to the start line. Soon I’ll be adding a 750m swim and a 5 k run to either end of my usual cycle, in essence i will become a Triathlete!

Running has always been my Achilles heel and i was hoping that the RS400sd was going to be the piece of kit to help me achieve my running goals!

When opening the Box I was delighted to see that there were three main components to this HR Monitor. The Polar RS400sd training computer which is worn on the Wrist. The Polar WearLink®+ transmitter which is worn on the chest and finally the Polar S1 foot pod which is, drum roll…worn on the foot!

I heard that they do sell the Polar RS400sd without the foot pod so I was really pleased to discover it was included with the version i was given. I first slipped the HRM onto my wrist and then fitted the chest strap and Footpod consecutively. The HRM itself is almost ‘stealth like’ in design and futuristic in its looks. In fact it’s so comfortable that i’d consider wearing it on a daily basis. Unfortunately the user interface (UI) seemed to be a little dated in comparison. I’m no technology expert, but surely for this price there must be a better UI? Why do I feel like I’m navigating through my grannies’ old Nokia phone?

Having said that; the features on the Polar RS400sd are quite extraordinary. Before my run I had to synchronise/calibrate the HR Monitor with the foot pod, which was done by pressing down and holding the red button on the footpod. That was it and I was ready to go!

On route, the HR Monitor provided me with an accurate Heart rate reading together with calorie expenditure, speed and distance readings throughout!


What really impressed me was the Polar SportsZone function which allowed me to personalize my own my five training zones. This was great as it gave me a very helpful guide on the intensity of my run. Like most people, I was wondering (perhaps even slightly apprehensive) about how this FootPod would actually “stay on my foot”, without me launching it into a nice hedgerow half way through my run? Would it be a nuisance? Awkward even? Surely nothing could be more awkward then my running technique!

 I needn’t have worried.. the foot pods weight is unnoticeable and it’s fitted on a type of bracket that slides down between the laces and the Training shoe Tongue. The bracket then clicks tightly back onto the Footpod itself. Quite simple and very secure. So secure in fact, that I feel confident leaving the Pod attached to my Training shoe indefinitely (Performing a brief recheck on it before my next run). Really though, “le morceau de résistance” for me in particular has to be the Polar Running Index.

Like most amateur runners I am really trying to improve my running fitness levels. By improving aspects of my running and breathing technique, I can significantly improve my times. The great thing is that the Polar Running Index allows me to measure that improvement!

The index takes the speed and distance reading from the footpod and measures that against my Heart rate data highlighting my current fitness level. I can then compare my result to previous or future result, making it easy for me to track my progress.

Overall I feel the Polar RS400sd is really great product. A few minor draw backs include the User interface and the ease at which buttons can be pressed by accident. This is a product which I’ve really enjoyed reviewing and which has altered the way I look at my training.

Full RS400sd details:

Body measurement features
  • Automatic age-based target zone – bpm / %
    To help you train safely and effectively, the training computer automatically determines your heart rate target zone limits according to your age-based maximum heart rate (220 minus age). The limits are determined either in beats per minute (bpm) or as a percentage (%) of your maximum heart rate. See also Manual target zone.
  • Average and maximum heart rate of each lap
  • Average, minimum and maximum heart rate of training
  • Heart rate – bpm / %
    Heart rate is the measurement of the work your heart does. Heart rate can be expressed as the number of beats per minute (bpm) or as a percentage (%) of your maximum heart rate.
  • HR-based target zones with visual and audible alarm
    You can define your target zones for a training session based on heart rate to help define the right intensity. When you are out of the preset zones, the training computer will give a visual and audible alarm.
  • HRmax (age-based)
    The highest number of heart beats per minute (bpm) during maximum physical exertion. For a rough estimate of your maximum heart rate, subtract your age from 220. HRmax is a useful tool for determining the intensity of training as intensity zones can be defined using HRmax. Some Polar products define maximum heart rate during the Polar Fitness Test, see also HRmax (Polar Fitness Test -based).
  • HRmax (Polar Fitness test-based)
    Some Polar products predict your HRmax simultaneously with the Polar Fitness Test. This predicted HRmax value is more accurate than the age-based formula (220 minus age).
  • HRmax (user set)
  • Manual target zone – bpm / %
    This feature enables you to manually enter the target zone that is suitable for your training. You can set the target zone for your training as beats per minute (bpm) or as a percentage of your maximum heart rate.
  • Polar Fitness Test
    Polar Fitness Test measures your aerobic fitness at rest in just five minutes. The result, Polar OwnIndex, evaluates your maximal oxygen uptake (VO2max). With the Polar Fitness Test you can measure your aerobic fitness by yourself, automatically and without any exertion. All you need is your training computer. The Polar Fitness Test is as accurate in predicting the VO2max as any sub maximal fitness test. The test is based on heart rate and heart rate variability at rest and personal information.
  • Polar OwnCal® – calorie expenditure
    Polar OwnCal calculates the number of calories burned during training. This feature allows you to track the calories burned during one training session and cumulative calories burned during several training sessions.
  • Polar OwnCode® (5kHz) – coded transmission
    Coded heart rate transmission automatically locks in a code to transmit your heart rate to the training computer. The training computer picks up your heart rate from your transmitter only. Coding prevents interference from other training computers.
  • Polar OwnOptimizer – personal training status
    Polar OwnOptimizer feature is an easy and reliable test to determine whether your training is optimally developing your performance. OwnOptimizer helps you to optimize your training load during a training program so that you experience an increase in performance and do not undertrain or overtrain in the long run. Based on the test, you are provided with a scale and description of your personal training status.
  • Polar OwnZone® – personal heart rate zone
    Polar OwnZone® determines your personal heart rate limits for a training session. Depending on the day and time, your physical state may vary, for instance, if you are stressed or tired, or if you are not fully recovered from your latest training session, Polar can determine that information from your heart rate and guide you to your ideal training zone for that moment.
  • Polar sport zones
    Polar sport zones provide an easy way to select and monitor the intensity of your training and to follow sport zones based training programs. Training is divided into five zones based on percentages of your maximum heart rate: very light (50-60%HRmax), light (60-70%HRmax), moderate (70-80%HRmax), hard (80-90%HRmax) and maximum (90-100%HRmax).
  • Training load – available via polarpersonaltrainer.com
    This feature is available in Polar software. When you transfer training results from your training computer to polarpersonaltrainer.com, you can follow your training load and recovery in the training diary. Continuous monitoring of training load and recovery will help you recognize personal limits, avoid over- or undertraining, and adjust training intensity and duration according to your daily and weekly targets

Data transfer

  • Compatible with PC via IrDA USB Adapter
  • Compatible with Polar ProTrainer 5 software via IrDA USB Adapter
  • Compatible with polarpersonaltrainer.com via IrDA USB Adapter

Polar ProTrainer 5 features

  • Advanced training analyzing
  • Reports
  • Training computer settings
  • Training diary

Polarpersonaltrainer.com features

  • Advanced training analyzing
  • Training Diary
  • Training Load
  • Training programs

Recording features

  • Adjustable recording rate – 1s, 5s, 15s, 60s
    Your heart rate, speed, cycling cadence, power and altitude data are stored either in 1, 5, 15 or 60 second intervals. A longer interval gives you more recording time, while a shorter interval allows you to record more detailed data. A shorter recording rate uses the memory of the training computer faster, but enables more accurate data analysis using Polar software.
  • Memory left indication
  • Totals
    Totals includes your training data starting from the last reset enabling you to follow your long-term training.
  • Training files (with summaries) – 99
  • Weekly history
    Weekly history gathers your weekly training data. By selecting a week, you can review your training data for the week.

S1 footpod features

  • Distance – training, lap, and total
    Distance (km, mi) can be set and measured in several ways. Training distance tells you the distance traveled during a training session. Lap distance tells you the distance of one lap. Total distance is the distance accumulated since the last reset.
  • Running Index
    Running Index is based on heart rate and speed data measured during the run. It gives daily information about your performance level, both aerobic fitness and running economy. Improvement in running efficiency indicates improved economy of running performance.
  • Shoe selection – settings for two shoes
    Shoe selection feature allows you to select shoes for a particular sensor in your training computer and to follow your training distance for the particular pair of shoes.
  • Speed/Pace – current, average and maximum
    Speed (km/h or mi/h) is measured with GPS, footpod, stride sensor or cycling speed sensor. Pace (expressed as min/km or min/mile) stands for the rate of speed. Pace is usually used in running. By setting a target pace, you can follow how fast you need to run in order to reach a certain distance in a predefined time.
  • Speed/Pace-based target zones with visual and audible alarm
    You can define your target zones for a training session based on speed. When you are out of the preset zones, the training computer will give a visual and audible alarm.

Training features

  • Automatic lap recording
    With this feature you can set your training computer to take laps based on preset distance, for example, every 1 km/mi.
  • Display zoom
    Display zoom feature allows you to zoom in information on the display during training.
  • Graphical target zone indicator
    This feature points out graphically on the display the zone you are in during a training session helping you to stay on the desired intensity zone.
  • HeartTouch – button-free operation of wrist unit
    When HeartTouch is on, different training information during training can be accessed without pressing buttons, for instance, when gloves make pressing buttons difficult, by bringing your training computer close to your transmitter.
  • Interval trainer guided workouts – heart rate / pace / distance
    Create interval guided workouts based on time, heart rate, speed/pace or distance guidance with up to three linked timers or distances and up to three target zones.
  • Number of laps – 99
  • Time and distance based interval timers
    Use timers, for example, as a training tool in interval training to tell you when to switch from a harder to a lighter period and vice versa. The timers can be time- or distance- based.
  • User configurable displays – all lines
  • ZoneLock
    ZoneLock feature helps you to accumulate certain intensity. You can either lock a zone before a training session or during it by pressing a button when you are on the desired zone.
  • ZonePointer
    ZonePointer is a visible and moving symbol on the training computer display indicating whether you are inside the pre-set target zone. This feature helps you to reach the desired intensity/pace/speed/cadence targets.

Watch features

  • Backlight
  • Date and weekday indicator
  • Display text in English, German, French, and Spanish
  • Dual time zone
  • KeyLock
    By activating KeyLock, training computer buttons are locked, and accidental presses do not cause problems, for instance, during training.
  • Low battery indicator
  • Reminders
    You can set reminders to alarm you of different tasks or training sessions, for instance, reminding you to drink during a training session.
  • Time of day (12/24h) with alarm and snooze
  • User replaceable battery
  • Water resistant – 50m

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