January 12, 2009

Polar RS800cx or Suunto T6c that is the question

How is that for controversial title? I have just recently received few question from people trying to decide between the two monitors. As you probably know I own both of them and do not plan to let one of them go any time soon. In fact I find both good at what they do, but if you have money just for one what should you do? Well you will need to decide for yourself, but this post will hopefully provide some information that make the decision easier.

I'll use the same format I used in the other comparison article in June of 2008 - Q: Garmin Forerunner 405 or Suunto T6c?. I made few changes to the T6c text reflecting my longer use of the watch. But most of it remains the same as 7 months ago. Note that I ultimately sold the Garmin Forerunner 405 on eBay after I got tired of it. I'm sticking with the RS800cx and T6c for now.

Training planning

Polar RS800cx - it will be of little surprise to readers of this blog, that I like the abilities to program variety of guided workouts in this watch. It offers so many options to structure workout that I have yet to find a workout I can not program in it. You name it - ladder intervals, sessions with various interval length, phases focusing in cadence, pace or HR. You can do it all. Do you need to workout for specific time or until your HR raises to specific HR, etc. So in training planning I really prefer the flexibility and functionality you get in RS800cx. You can define workout in the watch, but I prefer to use the Polar Pro Trainer 5 software to plan my training sessions.

Suunto T6c - has some planning capability in the software, but the guided workouts are to be defined directly in the watch. You can define warm-up duration, countdown duration (in case you want to do warmup, but not include it in the total exercise time), then there are two time intervals or you can use distance intervals (again only two). You can define how many times to repeat the intervals and that is it. I find this fairly good for less structured training sessions. So I use the T6c on simpler workouts - like tempo runs or recovery runs that are easily fit into the format of warm-up and two interval timers. (In June I wrote that I felt the RS800 was more robotic way to do the workouts - I do not feel that way these days. Perhaps I was on the edge of overtraining and needed to step back. The switch to T6c certainly helped that. These days I train with both and as I wrote above the RS800cx is for more structured sessions and T6c for sessions that have little less structure). The T6c is very similar in training planning abilities to S625X from Polar in terms of interval workouts.


Polar RS800cx - what I like in RS800cx is the ability to define up to 3 pairs of shoes with different calibration factors. So you do not need to mess with the CF before each run if you decide to wear different shoes or just switch from road to treadmill. The actual execution of the training session is very well supported by the watch. It has very clear and loud beep when switching from one planned phase to another. Also the limits alarm beeps loud enough to hear it if you exercise with headphones. The watch provides information about many parameters of your session from overall perspective or individual laps. After each lap watch briefly displays the summary for the lap and if if is changing from one phase to another it shows the new phase title. This is very useful when you have multiple phases and in the middle of the exercise forget what is next - the watch will remind you. I also like the little repeat calculator in the right bottom part of the screen that shows you how many repeats of the phase or phases are remaining. It is very useful especially in case of interval training when you may miscount - yeah it happens to me all the time. Another great thing on the watch is the display. It shows bunch of data which can be overwhelming at times, so I tend to stick to 2-3 displays that I configured to provide the key information I need (jut FYI the watch has 6 displays you can configure yourself, one multi-sport display which is discussed later in this text and one display for count-down of the current phase). The count-down display shows the counter of the current phase with time remaining and information about the limits - e.g. HR, cadence, etc. Other stuff that you may like in this watch is the recording of your location if you use the G3 GPS sensor, recording of cadence both in cycling and running. There is more about this unit in the three detailed articles I wrote last year after I had the watch for few weeks. I will not go back to that discussion here.

There is doubt that this watch provides the most functionality out of any HRMs I owned so far. The only missing piece is the automatic switch between the sensors - like from bike to run. But the watch manages that OK. You can stop the exercise, switch to the other sensors and start a new session. The watch will prompt you if you want to combine exercises and if you do so it shows a new display for multi-sport workout. The display shows overall time, distance and calories burned in the combined session. You can combine multiple sessions into one and then review them later in the software.

Suunto T6c - works like a charm for running and biking (and with memory belt also OK for swimming). The watch is able to automatically switch between sensors (pods) if you use multiple in one session - bike pod, foot pod, GPS pod. Like in the triathlon race. The comfort HR belt is very nice - I find it even more ehm comfortable than the Polar WearLink+ and it works very well once you figure out which part to moisten. The watch has configurable screens - 2 screens 3 lines each and the last line can show multiple items that you can switch between. Other that that the watch displays the EPOC and TE on the fly, but I find these values less accurate than what you get later on the computer.

The really cool feature of this watch is the automatic switch between the sensors. I did a brick session and it recorded my bike speed / distance (as 18mph), then I did a lap for transition and headed out of the house for a short run. Before I hit the street it was already switched to my foot pod and was showing my pace 18:30/mi as I walked and soon 7:45/mi as I started running. It is pretty cool to see this working after struggling with this with Polar, previous Suunto and Garmin. This may not be as important for single sport athletes, but quite nice for triathletes. Especially if you want to have one less thing to care about in transition. That is also one reason T6c will remain in my collection. I plan on racing with it again this season.

Evaluation of training

I guess this sentence from original article summarizes it well: "Well compared to Polar software both Garmin and Suunto have a long way to go."

Polar RS800cx - Polar Pro Trainer 5 offers certainly the software with most bells and whistles for analysis of single workout or reporting over a defined period of time. I love the ability not only to define own sports, but for each to set the speed/pace units that I want to see in the graphs, different HR zones for each sport and the ability to define my own reports and customize how they look. You can easily take any set of HR zones and synchronize them to your watch in case you wanted to switch between them for cycling or running session. The calendar view and summary for the week is also quite useful and shows you actual vs planned - number of exercises, training time, distance and actual burned calories.

I also like the way Polar stores the log files in individual text file. I can modify the logs if I need to correct data from the session. Like this past weekend when I had an occurrence of CS600 not connected well with my HR belt. After the session I had all HR data in RS800cx log and all the power, cadence, speed data in the CS600 (but no HR). I simply took the logs opened them in text editor did one large copy/paste and saved the log. Everything was saved and I could do the analysis I needed to do with HR, power data. While I had few cases when CS600 did not capture my HR data I never had issue with RS800cx. If you are interested in R-R data analysis the RS800cx can capture the data and you can later analyze them in the Polar software (which has very limited analysis functions) or load them to other R-R analysis tools like FirstBeat Athlete or Kubios HRV.

Suunto T6c - the biggest difference between T6c and other HRMs is the analysis of your workouts to provide EPOC and TE. The standard STrM software does the basic analysis and shows you the data recorded by the watch - R-R data, HR, speed / distance and all the parameters the software calculates based on the R-R. I use also the FirstBeat Athlete software mostly to help me look at my EPOC load during the week and month. The STrM is not as flexible as PPT5 and while it allows definition of multiple sports it supports only one set of HR zones. I find the analysis capabilities of the software little limited compared to PPT5. The only exception is the TE and EPOC that Polar does not provide in their software. But if you use the FirstBeat Athlete you can get the EPOC and TE post workout if you load the R-R files to the software. I found the fine tuning of the parameters for the accurate EPOC/TE calculation somewhat complicated when I first got the watch. But that is no longer the case since Suunto published the manual from Eddie Fletcher that describes how to best setup the watch. Key is to determine your activity class based on your weekly training load and your VO2max either via lab test or based on field test or race result. The manual provides great examples and makes setting-up the watch much easier than before it was published.

Daily use as a watch

Polar RS800cx - I wore the RS800sd on daily basis for over a year and the RS800cx is the same 'format'. It fits well under shirt and can be used as daily watch. It is just a tiny bit smaller than the T6c, but it is hardly noticeable. The alarm of this watch works fine and can be snoozed for 10 minutes if you want to get more sleep.

Suunto T6c - It is a watch that you can use daily. It fits under the shirt and goes with pretty much any outfit (especially the black version that is not as flashy as the Fusion). I pretty much alternate between T6c and RS800cx as my daily watch. I do not mind wearing either one of them. You may prefer Suunto if you need multiple alarms to get out of the bed - T6c has 3 of them, but does not offer snooze.


Note that this section reflects the situation as of January 2008 and that I looked at prices on US market. The prices are likely to change over time so do your research, check sites that sell Polar and Suunto watches. I also strongly recommend to only buy from certified distributors and resellers of Polar and Suunto to prevent any warranty repair issues. Both Suunto and Polar confirmed in telephone that they honor warranty from Amazon.com where I made most of my purchases in the past few months of HRM shopping.

Polar RS800cx - the watch alone is now about 400 USD + tax. You can also buy a package with the watch and either S3 sensor for running (470 USD), multisport package with G3 sensor for 470 USD or bike package with bike speed sensor for 430 USD. The additional sensors go for 140 USD for the S3 foot pod, 130 USD for the G3 GPS sensor, 55 USD for cadence WIND sensor and 55 USD for bike speed sensor WIND. Do your math before you buy as certain combinations of packages and additional sensors could be less expensive than others.

Suunto T6c - The watch sells for 335 USD for Black version and 350 USD for Fusion version. The foot pod for 80 USD, bike pod for 50 USD, the road bike pod for 57 USD and lastly the GPS pod for about 150 USD. Suunto also offers various packs with T6c - Triathlon pack with all you need for triathlon including memory belt for 660 USD, Running pack with T6c and foot pod for 470 USD and Multisport pack with GPS sensor (does not capture location) for 530 USD.


Well you will need to make one for yourself. If you can go look at both models in the store or at the race expo and test them out before you purchase. They are both very good HRMs and will help you structure your training. As for me I'm going to keep both of them on my wrist as I train. One at a time to be exact. I will cotinue to use the T6c for less structured sessions and RS800cx for sessions that are more complex. I will continue to run road races with RS800cx and do triathlons with T6c. Let me know if this helped a bit in your decision making.

Update (13/1/09): In case you want to read more about the RS800cx you may like to review few earlier articles on this blog:

RS800CX - more detailed review of the functions I.
RS800CX - more detailed review of the functions II.
Analysis of training data (part 3 of RS800CX reviews)

There are also few articles about Suunto T6c that I published earlier.


Jay said...

Thanks for the great review.. funny how I was just looking between these products (and the Garmin 405). Stumbled on this and you just posted it like 40 minutes ago. Seems like the Polar is more for me.

kxux said...

Yeah that is too funny. Enjoy whichever you decide to get. They both work well.

You can look at some older posts about RS800cx where I reviewed it in detail to make up your mind. I may just link them to this post for people that may want to get more info.

Good luck.

Anonymous said...

Thanks for this in-depth review.
Polar is quite huge, I do prefer T6c more.
But in the very end, I went for the simple Forerunner 50. Polar and Suunto both lack Mac support.

kxux said...


it is interesting choice to go for the Garmin 50 when you looked at T6c and RS800cx just because of Mac support. I use both T6c and RS800cx on my home Mac with Parallels and it works just fine. But hey you had your reasons.

In my opinion the Garmin 50 is more comparable to basic models like T1c or T3c from Suunto and RS100/RS200 from Polar. I had one for about a week just to test it out and returned it to the seller. It did not fit my needs.

kxux said...

Oh one more point of clarification - the T6c and RS800cx are almost the same size. Polar is not bigger that T6c. If anything it is a hair smaller. It feels smaller on the hand anyways due to the curved design that helps when you move your wrist.

Santi Millan said...

Thanks for the really usefull review.
I'm trying to decided between both and with your review some of my doubts now are much more clear.
One doubt i've got an nobody talks is, the pod for run in polar and suunto is enough accurate in trail?...i use to run a lot in the mountain.
Your blog is one of my favourites.

Anonymous said...

Oh, I know that T6c and RS800 are in a league of their own!
I went for the FR50 because I'm a Mac user, and a newbie in training resources. A compromise.
If Suunto made a Mac version of their software, I'd switch for sure (I love Suunto watches!).
Thanks again!

Jay said...

Yeah, mac support is a big deal for me too.. however, I have been running VMware Workstation on linux to get my windows fix for years. So I just use it that way now that USB support is decent. My mac is a quad g5 so I haven't went to intel to be able to run fusion. Maybe one day we can get real mac support but until then thank goodness for virtualization.

kxux said...


I do not do much of trail running. But from what I have observed on the discussion forums the foot pods are pretty accurate on trails as long as you have pretty stable footing. If you run hard trails you may get better results with the GPS sensor.

Santi Millan said...


Thanks a lot for your explanation. I supose i'll try first with the foot pod and if the acurracy is bad i will try with the gps.

I've got a question? how long are the swimmingpools in the USA? i ask you because here in Spain we use international system (meters) amd is very dificult to follow your test in yards. I supose your pools are 30yards long...here are 27.4 yards.

Good luck and train hard

kxux said...


most pools are 25yd long, but it all depends on the facility. Just like running track we may have mix of metric and imperial length pools. So some pools will be 25 meters while other will be 25 yd (22.86 m). The difference is pretty small, but it adds up over the duration of the swim. I keep track of all my swimming paces in s/100 yd to keep it easy and avoid unit conversions.

Anonymous said...

Hi, excellent review! I have a quick question about loading RS800cx data into FirstBeat. When PT5 saves an exercise from the watch, it creates two hrm files, one with R-R data and the second containing distance data, cadence, etc. I tried to open both hrm files with FB, but only the R-R file was recognized. So, I am able to view EPOC, TE, and HR data in FB, but no graphs involving distance, pace, cadence, etc.

Is this your experience too or are you using a different method to get Polar data into FB? Thanks!

kxux said...


yes that is exactly my experience with FB Athlete and Polar R-R files. I really look at the speed / pace / distance / laps / etc. in PPT5 and use the FB Athlete for EPOC/TE analysis of the R-R file. Even for Suunto logs I do not look at the pace, splits or lap times in FB Athlete, but stick with STrM for that purpose. It actually is OK for the one workout analysis. Just the reporting is not as customizable as what PPT5 offers.

By the way FB has a known bug for lap times for the Suunto files and it is not really usable at this time anyways.

I know I hear you all I tend to answer and give you always some more to mull over. Oh well that is just me.

Anonymous said...

Thank you, much appreciated.

Claude said...

Thanks for the best review of Polar and Suunto that I have found to date. After researching HRM watches for the past several weeks, there are a significant number of problems that folks are reporting with the IrDA USB adapter interface and the RS800s. I am having a hard time looking past this negative feedback and Polar’s apparent lack of attention to this matter. The polar has everything that I am looking for in and HRM watch, but it would be useless to me if the data is not easily retrievable. Thanks again and any feedback is appreciated.

Anonymous said...

"T6c GPS sensor (does not capture location)" - means you cant record track of your trips or just doesnt show you on the wristop and is recorded for later use? RS800cx can show the track in a map, which is nice feature for me.

If the GPS is "just" for speed measuring then Ciclosport HAC5 with RDSII comes into game - any experience with that?

kxux said...


I'm not sure what problems you are referring to. The Polar IR interface is as stable for me as the wired interface that Suunto uses. I did not experience any issues with the IR interface on my machine. And I have been using this interface for 3 years now (first with S625X, then RS800sd and now RS800cx and CS600).

I understand some users had issues with drivers on Vista, but I can not really comment on that as I do not use Vista. I suggest you to check the Polar forums for details.

kxux said...


I do not have experience with the watch you are referring to.

I do not think I'll test it as it does not seem to be appropriate for triathletes as it does not have any running functions - from what I can read on the manufacturer website.

Anonymous said...

I think HAC5 can measure speed and distance using RDS (Doppler radar). However I decided to get RS800CX, for its "tracking" feature. Thanks much for a great review that helped me to choose. (díky moc ;-))

Anonymous said...

Great reviews! Thank you--best reviews out there... :) It's possible I may have missed this somewhere in your commentary, but can the RS800cs be used in the pool? If a triathlon is your end goal which watch and any related accessories would you recommend? Thanks for your help!

Anonymous said...

Dumb question. If I select the T6c and the GPS Pod, will I obtain the same information as I would using the Foot Pod and Road Bike Pod. I am not concerned with cadence. I am concerned with pace, speed, distance, calories and the effectiveness of my training.

kxux said...

Tazzy - neni zac ;-)

Anonymous - the G3 provides the pace, distance information just as the S3. You can just expect little higher spread of the immediate pace while running. The GPS technology is not as accurate as the foot pod. But works just as well over longer laps. Calories burned do not come from the sensor, they are determined based on your personal data and intensity of exercise - e.g. heart rate.

The RS800cx can be used in the pool, but you will not receive any HR reading as the WIND technology does not transmit under water.

Training for triathlon with RS800cx - my preference would be bike speed, cadence and S3 foot pod. The G3 as optional if you want to do mapping. If you are training recreationaly and do not worry about cadence then you can go with G3 as the only sensor. But if you want to improve on the bike and run cadence is pretty important part of training.

erdooom said...

hi, i use my heart rate monitors for cycling and freediving. Sadly there isn't a freediving heart rate out there yet. I do use a polar rs400 and s725x for my pool session, they both recored my heart rate underwater fairly well. Which of the 2 watches you reviewed works better under water ? for me the t6c has a big advantage in that it is waterproof to 100 meters / 330 feet.

kxux said...


I'm afraid neither one will give you HR under water real time. T6c in combination with memory belt would give you HR post exercise as the memory belt captures the HR and you can then combine it with the T6c log in the software. I do that in triathlon races - the memory belt records my HR during the swim and the watch picks up the HR once I'm heading into T1.

Jim Mc. said...

Thank you for the great info on the two HRM's. I am really struggling on which to choose. I am not an extreme athlete, more of a weekend warrior, mtb and running. Looking to make the best use of my training time. The key for me is the best feedback as to how hard I should workout. I do like to plan out my workouts and track the results. The polar software seems to be better at maintaining workout plans/results than FirstBeat. Can I get info similar to EPOC/TE with Polar, I'm ok with it not being on the watch. One last question based on the fact that I am not an endurance athlete am I crazy to go for one of these high end watches?

kxux said...


I know it can be pretty hard to decide which of the two is better for you. I went through the same process only with the benefit of using both for a while.

Both of them will give you EPOC/TE post exercise (the T6c also during the exercise). Polar has more functionality to structure your workouts the way you want them - e.g. specify HR limits specific to phase for up to 12 phases each one or each group of them can be repeated as many times as you need. It is very flexible in the way you can structure your sessions (if you need to). On the other hand the T6c has the EPOC/TE during the session although its ability to support guided workouts is limited (e.g. HR limits or pace/speed limits - can not be combined in one session and you have only two time or distance based intervals plus warm-up interval).

From comfort perspective the belts are very comparable and work pretty much the same way. I did not experience any major issues with either one of the belts in cycling or running (and they both do not work in water).

You say that you are looking for feedback how hard to workout. I guess what you are looking for is the volume and intensity guidance for the workouts. In my workouts I follow the HR zones as specified by Joe Friel (with exception of running where I initially used HR zones, but lately I stick with my pacing zones determined from actual race results). I have never used EPOC/TE to manage my workouts intensity (well again exception being the easy sessions where I aim not go go over TE of 3.0).

On your last question whether it is appropriate to consider top of the line HRM. Well it depends - I guess my wife when she runs she does not really care much about her HR and although I can try to convince her to use one of the HRMs in her workouts it is not going to click with her. She does not care about all the data - she cares about getting the miles in and being physically active. On the other hand if you are more of a analytical type and enjoy digging through the data and analyze how you improve over time you will by all means enjoy the top of the line HRM that gives you the information. But always remember body is not a computer and sometimes running without the HRM or without looking at it does not hurt you :-).

Cyril said...

Thanks for the review,
I am not a triathlete, just a simple guy going back to the gym to get slimmer :)
I had an old polar with a belt (not coded) from ebay with the old infra red link, until it's battery died.
Since new year I use a new forrunner 50 with the footpod and belt, simple easy, and the ant data transfer is far better that the IR of the polar, it's perfect for inside treadmill.
For the summer, I plan to order something with a gps so I can see my run (I am a geek !). I was looking at the garmin 405, but after reading your review, probably go to the polar rs800cx kit.


Jim Mc. said...

Thanks for the additional answers on the monitors. I am definitely an analytical type and love digging into the numbers and I'm also a techno geek. My wife is ready to kill me, I've spent the better part of February investigating these two watches during the evening hours. I've downloaded the evaluation copies of Polar, Suunto and FirstBeat. Polar has them all beat when it comes to planning and managing the workouts. The only thing that was pulling me towards the t6C was the on watch EPOC/TE values but I don't see myself altering my workouts halfway through based on those values. So the RS800 wins based on the following, ability to download workouts to the watch, software is better for planning/managing workouts. Footpod offers cadence and running analysis, t6c does not. Looks like I'll end up purchasing the FirstBeat software for the EPOC/TE analysis but I probably would have done that anyway. You've been a huge help with all of the info you provided

Carlos Rafael said...

Hi kxux

I'm more or less weekend sport warrior, and would like to buy a more accurate equipment. Also one really uncomplicated to use. Which one would you suggest? Don't worry I would not blame you later :-)

Ps: Great Blog, really helpful!!


kxux said...

Hi Carlos,

thanks for your comment. Depending on what sports you are doing and what you consider complicated. You can go with pretty much any Polar or Suunto watch. Both of them make great products. The range of products is pretty large so I do not want to get into speculations. What sports / events do you train for. I do not want to make any assumptions.

I use both RS800cx and T6c because T6c has some less functions. Like yesterday for my long run I was unable to program this in the watch: 80 minutes steady long run at prescribed pace and then 4x (30 second pickup to 90% sprint followed by 2 minutes recovery). I used RS800cx for this as the watch makes it possible to define guided workout exactly for this session. T6c unfortunately has only limited set of interval timers and could not guide you through the session. I hate to look at the watch during the pickups and estimating 30 seconds while running 90% sprints is not very easy either.

While RS800cx is the most complex watch I ever owned anything I trow at it it is able to do it. With T6c there are some limits. You just need to recognize them and work around them when you hit them.

Jay in SF said...

Great review!

A question about swimming: I'm currently using the Polar s725x for basically everything I do, to include swimming, but I read somewhere that the Suunto Memory Belt transmits at 2.4Ghz and its signal can be picked up by the Suunto T6c. Any idea if the T6c can record the signals from the Suunto Memory Belt while swimming?

Basically, I don't want to record everything once I put the Memory Belt on, but only once I start working out.

I hope to do a triathlon one day and I'm a nerd when it comes to analysis (currently using VidaOne software to look at my Polar data, in addition to PPT5), but I'd like to eventually move on to something like Firstbeat Athlete to help me get even more disciplined with training.


kxux said...


thanks for the questions. The S725X uses 5kHz signal that travels through water just fine. The new models from Polar and all Suunto models use digital technology that does not travel in water. The Suunto Memory Belt helps capturing the HR during the swim (and the HR does not appear on the watch for that duration). Once you get out of the water the HR picks up and shows on the watch. The Memory Belt can be set in two modes - recording mode that records all HR data to internal memory or the transmission mode that only sends the signal to the watch just like normal HR belt. In recording mode the belt records and sends data to the watch (watch can then record the data as well). It sounds complicated, but it is not. What is cool about this is that you can take your memory belt HR data and merge them into your T6c log after the exercise. This way your tri or swim log will have complete HR record. The recording in water has its problems (not only with Suunto) and in some cases may provide sub-par info. I have best results when using the memory belt under race suit or wetsuit which keeps it in place and does not let water between the belt and the body.

The FB Athlete is a good application. I have some doubts about the coach function at some times (like when it recommends 4.x workout after 4.9 workout), but the rest of the software is great. I'm sure FB will be making changes to the coach in the future. Perhaps it is the activity class that I use that the coach is less useful. I have seen people happy with it up to AC 7.5. Best is to test the software for 30 days before you buy it. I suggest to do that once you have a watch that captures R-R data. Prior to that you will be stuck with just providing average HR which does not carry as much data for the tool. Good luck.

Jay in SF said...

kxux, thanks for the info!

Three more questions, if you don't mind...

- When downloading the memory belt data, can you edit it? From what I've read of the Suunto memory belt, once you put it on it starts recording. What if I put my memory belt on and I don't get into the pool for another four or five minutes to do laps? Can I download the data and edit out that portion so that I only have the actual training time to analyze?

- Having used both Polar and Suunto, have you noticed if there's a correlation between the standard Polar training zones and Suunto's Training Effect/EPOC? It seems that Suunto's TE works off of the training zone theory and tells you which zone you've spent the most time in.

- And... I know with my s725x and other Polar models, it doesn't really start counting calories until you're over 100bpm. I think per Polar, they don't consider anything under 100bpm aerobic exercise. Is Suunto the same way?


kxux said...


- editing of the data from memory belt is not possible in the software other than splitting it just as the normal T6/T6c log. But when you merge the T6c and Memory Belt log only the overlapping time period is reflected in the resulting log. So no matter how long you wore that Memory belt before start of the race - you can get a log that has only the race period in it.

- HR training zones - I do not use the Polar recommended zones I do use zones according to Friel's Training Bible that are based on threshold HR. There is definitely a correlation between the HR and EPOC. You can actually see it in the FB Athlete software when you enter workout manually and do not have TE/EPOC data only average HR. They use the average HR over period of exercise to calculate EPOC/TE.

- Newer Polar units count calories even before you reach 100. I do some recovery rides with my HR in around 80-90 bpm which would on S625X net me 0 calories. On CS600 and RS800cx it gets me some calories burned. Suunto is the same way - as long as you wear the belt it calculates calories.

Anonymous said...

Thanks for the review. How would you compair the battery life of these two HRM's and the sensors Do they make rechargeable battereis for these?

kxux said...

The watch battery life is about 8-10 months each - depending on use. Much better than rechargeable watches.

Sensors - foot pod usually lasts about 25-30 training hours, GPS pod between 6 and 10, bike pod I do not know Polar speed sensor for the bike does not have changeable battery and they quote 1000 hours of use I believe and will replace it if it dies earlier. Suunto bike sensor I do not use nearly enough to say. I usually put new battery before first race of the season and just as precaution replace by middle of the season.

You may want to use rechargeable batteries for the GPS sensors where Suunto uses AAA and Polar AA battery. I do not use rechargeable ones as I do just limited training with GPS sensor.

Jay in SF said...

kxux, thanks again for the good comments. I think you may have actually saved me some money. I like to get real-time info when I work out, even when swimming, and neither the RS800cx nor the Suunto T6c would actually give me that while in the pool.

With regards to Training Effect -- I'm a geeky analyst by trade -- so what I've done is just set up a report in PPT5 that shows the following:

- Time in Sports Zones (my zones are based on the Karvonen Formula)
- Average Heart Rate
- Polar Optimizer Results
- Recovery

It may not be as fancy as FIRSTBEAT ATHLETE, but at least by seeing which zones I'm training in I can get a rough idea of how much time I'm spending in the high zones and when I need to recover.

I'm not sure what parameters I'd need to set up a report for EPOC -- I reckon I'd need recorded R-R data for that -- but at least a quick glance at Training Effect report should help with all of my work outs.

kxux said...


you can still use the TE in FirstBeat if you want to - they can calculate it based on average HR. But you can also take advantage of the Exertion calculation in the PPT5 which is a good indication of the training volume and intensity - very similar to how the TSS is calculated in the WKO+ (less sophisticated though). You can define the Exertion parameters in the sports HR definition under Factor and Max Exertion.

Hugo said...

Thanks for the review..very helpful.

I am a weekend runner and biker but I am a high tech fan as well. I usually do not combine sports, either i decide to go running (usually not complicated stuff, warm up, run, cool down) or go biking which i love and then i would be interested in improving the cycling technique. I do like the possibility to export the track to google maps. I am however doubting for which model would suit me best. i do love the looks of the rs800cx pro but i dont quite get why do you use the suunto for simple exercises... and since mine are pretty basic as well i wonder which one would be best. If you had to do basic running or cycling (not same day) but getting all functionalities which one would you go for?

thanks in advance

kxux said...


I keep the T6c around because I can. It is more of a choice and switching between the watches - I'm Gemini and we like to mix things up a little :-).

If I had to use only one watch I would use Polar RS800cx PTE - no doubt about it. The sensor switching aside it is the watch with most functions and flexibility.

T6c is solid HRM that does great job, but the functionality lacks behind what Polar and now also Garmin offer. Besides the T6c does not do any mapping and if that is what you want you need to look at Polar with G3 or Garmin 403 or 310.

chalobb said...


Great review. I would like to ask you personally what would you recomend for someone who just started running and interested in buying a HRM? I'm looking at the Polar RS300X sd and the Suunto T3c running pack... i know you're not writting about those but i can clearly see you have a lot of experience in the field. I would also like that my HRM could work for swimming.

kxux said...

chalobb: Great question. As a matter of fact I have been playing with RS300x and T3c over the past few weeks and plan review (when I get to it).

Since you want your HRM to give you HR in the water the RS300x sounds like a better fit since it will give you that.

Otherwise they are both very similar in terms of info they capture during the laps (e.g. HR, speed/pace, distance, averages for lap, etc.).

Polar has more functionality like OwnZone, OwnCal, etc. Suunto on the other hand has the EPOC/TE which you can not get out of RS300x (unless you use the FB Athlete and estimate the EPOC/TE from average HR which the last version of FBA does, although it is not as accurate as direct calculation during the exercise). There is one caveat with the EPOC/TE in the watch - it may be little off due to computing power of the watch. I wonder how much off it really is and may test it with T6c and T3c used in the same workout. T6c can be little off, but the fact that the watch records beat-by-beat info it can correct the error in the software. Not sure how T3c stacks up in this regard. So much to check out ;-).

I used the RS300x in few runs and on few swim sessions and it is solid watch. My wife ran with it in few training sessions and one 5k race and she liked it. In the race she used the foot pod to pace herself since she usually starts too fast and this way she was able to run without stopping.

Raymond said...

Hi. Thanks for the insightful reviews. I've had a S625X for about 5 years and am looking to upgrade to the RS800CX. For triathlons, would you recommend the Multi plus the S3 footpod, or the Run with bike sensors. I don't need mapping but I'd probably use it for fun if available.

Which do you think provides the most usable data?



kxux said...

Ray look at this discussion on Polar website for my answer - I believe you started it right ;-).

HudsonX(阿晟) said...

Hello kxux,
Thanks for your nice review!
I got a suunto t6c about 1 month ago.
It's a great HRM!!
But I have some trouble about Foot Pod/Road Bike Pod auto-switching~
When I wear the shoe with foot pod to ride my bike for training, t6c sometimes switch to wrong pod(show foot pod info while cycling).
Any suggestion for this issue??
Thank u so much!

inv said...

Thank you for the very detailed review of these monitors.
Do I understand right that it is possible to use RS800 with FB athlete and has ET value from training? Also, I would like to ask a question: I started regular daily trainings 6 months ago, but the problem is that I do not know should I push harder or lower during training. Looks like ET is the value which I need. RS800CX/CS600 and T6C is expencive devices with have R-R/EPOC/VO2max logs which should be connected to computer to get current ET value and I am not sure that so much functionality will help me at my level. That is why I am looking at getting suunto T4C or T3C.

So the question is: is it ok to build training based on ET only?
And does suunto coach from T4C or from FB athlete helps to build base training level and track it. Or copy of calendar from cyclist's training bible + pen is the better, but requires more attention, solution?

PS: Sorry for my english.

kxux said...

HudsonX: I would recommend to remove the foot pod from your shoes for the biking. If there are multiple active sensors the watch may not select the right one.

kxux said...


Yes you can get the R-R data from RS800cx and process them in FirstBeat Athlete software to get EPOC/TE from your workout.

As far as training it is important to have a good balance of hard days and easy/recovery days in your training plan. Generally it is recommended to have 2-3 build weeks and one recovery week. Plus each week should have a combination of hard/easy days. If you find you recover hard from 3 weeks build you may benefit from cutting back to 2 weeks build and week recovery. If you can afford it find a coach if only to review your training plan and give you pointers what to focus on. I work with coach for about 12 months now and see a huge improvement in my training efficiency.

As far as building only TE based plans - well that is not as easy. You always need to decide what kind of session you will do to achieve that TE - e.g. are you going to have a TE2.5 session to build endurance with long run or are you going to do 2.5 run that is a short warm-up with speed drills. This is very much dictated by the event you are training for, your experience as athlete and training needs.

The coach built into the FBA and T4c does not have a lot of built in intelligence at this point. All it does is trying to improve your activity class through varying hard/easy training days and rest. There are actually research papers on FB site that you can review for details on how this actually works.

jst_chile said...

Excellent review, very professional, very accurate... seems that I'll go for the Polar, as I'm a beginner in the mountain bike.
Thank you, great and helpful job.

bellullabob said...

Great review and thanks for posting your experiences w/ these devices. I am a cyclist, and since winter is coming, I'll be spending most of my time on the trainer (don't do well in the dark and cold) and am wondering if the speed sensors for either the Polar or Suunto will work if mounted to the rear wheel? Thanks.

kxux said...

bellullabob: I hear you about the cold and dark. Not my favorite either.

Both Polar speed sensor and Suunto bike sensor (not the road bike sensor) work on the rear wheel on the trainer. I have been using Polar sensor most of the time since I use Polar power meter as well with the CS600 bike computer. Works very well both on the road and trainer.

syl said...
This comment has been removed by the author.
syl said...

hanks for your very quick response! I have one more question for you (at least for now). How sturdy is the watch? I am a mountain biker who does occasionally take a good spill! Also I know you upgraded to the pro version of the rs800cx. Is it significantly stronger than the non pro version (metal vs plastic)? Thanks. Btw, I don't remember if you made note of this, but to my disappointment I found out that any Polar equipment bought off of Ebay voids the warranty....

sigd said...

review is great thanks, but I am still in doubt which one I should use for my first Ironman, and on accuracy what do you think is better s3 or suunto footpod

Anonymous said...

Hi Jan,

I recently read that both the speed and cadence sensor did not have replaceable battery. Could you verify this as true? IF this is correct, do you know how long these sensors are supposed to last before you have to replace them? Thank you.

kxux said...

syl: sorry this one took little longer (work, training and life in general got in the way). Well the RS800 does not feel as sturdy as say S625X which was my first Polar watch. But it can withstand normal use just fine. I was surprised that the crystal does not get any scratches even after months of use (this was the same for RS800). The original RS800 had issues with watch band coming off, but I have only heard about one case with RS800cx and did not experience this myself. So while the watch does not feel as sturdy I did not have issues with it not being able to withstand use in workouts or as daily watch. I do not see any difference in sturdiness between the regular RS800cx and RS800cx PTE.

Yeah Polar is pretty specific about it - they use the re-seller network to sell their watches with warranty. I'm sure some of the sellers on eBay are Polar authorized and will be able to provide you with receipt that is valid for service. Or just use Amazon or other Polar re-seller. I buy most of my watches from heartratemonitorsusa.com - they are very close to where I live and provide great service.

kxux said...

sigd - it does not really matter. The difference in accuracy of the S3 vs, Suunto foot pod are negligible. And once you calibrate the foot pod they work well - both of them. I tend to race triathlons with T6c for its easy/automatic transition between sensors with no or minimal user intervention. Polar is little more complicated to switch from one sport to another. On the other hand Polar rules in terms of pre-defined workouts. Suunto provides very basic features for guided workouts. And then there is the new kid on the block we did not talk about much - Forerunner 310xt (not really a watch, but definitely a great training computer with triathlon capabilities). Hard call.

If it was only for racing I would go with T6c, if it is for training and racing I would stick with RS800cx. I still have reservations to 310xt (I have been using one for about 2 months now and while great in some situations there are still many issues Garmin needs to work out - like synchronization of data between PC and HRM, transfer of workouts with pace limits from PC to watch - they forget pace info and do not remind you when you slow down too much).

Best is to write down what is important for you and then decide on which of the watches provides best support for what you need. I know that is a non-answer, but this is something that is very individual.

kxux said...

Anonymous - both speed and cadence for the bike are sealed units with guaranteed lifetime of 3000 riding hours which is good for me. Should last quite a few years. I have heard of some people having issue with the sensor and Polar replacing them without any issue.

michael said...


Thank you so much for the detailed comparison between RS800cx and T6c. You have a wealth of knowledge here, and I am very grateful that you are sharing it through your blog. You mentioned that you find the real-time EPOC/TE measurements on the T6c less accurate than what is calculated post-workout in Firstbeat. How big is the difference in accuracy, and how useful does this make the T6c real-time EPOC/TE measurements in practice? I am leaning towards the 800CX PTE, but the only potentially useful feature for me that is missing is the real-time EPOC/TE measurement. Thanks!

sigd said...

kxux, thanks,
I am very happy with my rs800cx, and I have to say is very reliable, I experienced already the 310xt but in the middle of a 70.3 dropped me leaving without any data which was very annoying.
suunto I still think have a bit to go in term of software and plus reading your review gps unit which I would need to do my cross country skiing look like completely unreliable. I have to admit that at the beginning the garmin was good and I was very inclined to keep it even because I use the edge 705 for cycling and power training and I found it a wonderful unit. But the accident at the 70.3 completely put me off

cisco said...

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kxux said...

Michael, the EPOC/TE in the watch is quite accurate for steady state efforts like long runs, tempo runs and such. It gets little less accurate for interval training as the watch has less computing capacity than computer (plus there are some intricacies of the algorithm that work better for post exercise analysis - as Suunto experts indicated on the Suunto forums). I do find the EPOC/TE very close for steady state effort +/-5 EPOC which usually matches the TE. For intervals it differs and I can see error of 0.1 - 0.3 of TE which is still pretty good. All depends on how much your HR varies during the interval training (e.g. how much recovery you allow) and how long the session lasts. Overall the EPOC/TE will always be more accurate in the computer, but the watch provides good enough guide to keep you from going too hard.

If EPOC/TE is what keeps you interested in Suunto and deciding between RS800cx and T6c one other thing to consider is that there are not many plans based on EPOC/TE, but you should not have problems finding training plans based on HR or HRR. You can use both units for HR, but only Polar does HRR and %HRR. Another consideration to make.

kxux said...


good point about 310xt - I do train with it, but do not use it in races. I did not have any issues myself in training, but do not trust it enough to use it as the sole unit in a race (well except local 5k where it performed quite well). One thing I still can not grasp is why Garmin does not show split time - I get all the lap times, but not a split time from the start - very weird.

There are many reports of unit freezing-up mid-race or during regular operation (including yours). I think Garmin needs to fix the firmware and that will take them few more updates. Good thing is that they can do this after release of the product and I knew this will be most likely the case with the unit.

For tri races I stick with T6c - mostly time keeping and pace on the run and CS600 on the bike. Once or twice I used RS800/CS600 combination and that worked quite well, but I just got very used to the T6c during races that I just stick with what I know. In the end it does not matter what you have on your hand as long as it helps you achieve your goals.

Bats said...

Great review, still confused between the 2. I have 17 yr old who is about to start major league football (Aussie Rules - like your football)yep we live Down Under! Does a lot of 3km & 5km runs and also heaps of sprints etc. He wants to measure (over his training sessions) time on sprint, time jog, time walk, best recovery & EPOC. I'm confused 'cos I'm going to buy it for him. Does he need the GPS stuff as well or just the foot POD and watch/monitor. PS. He's pretty good at analysis so the computer stuff will be ok with FirstBeat Ath etc.

kxux said...

Bats, what is your budget? You can get speed and distance unit that is little less expensive. Also question if he needs to record R-R (or HRV) for detailed analysis in FBA. If not there are options as follows:

In Polar camp - RS400, RS300 would be good alternatives

In Suunto camp - T3c and T4c

All of the above work with foot pod and that should be sufficient for tracking the speed/distance for run training.

If you are not concerned with budget I consider RS800cx more of a watch than T6c. T6c has pretty limited number of options and I prefer it mostly in triathlon races as it handles transition from one sport to another better (e.g. I do not need to tell the watch I transitioned, it figures it out all by itself). Lately I have been training more with RS800cx as I'm ramping-up for fall marathon. Most of my training has been running with some swimming and biking as cross training. Definitely a run focus and RS800cx works real well.

If you get the RS800cx I would get the foot pod first and then consider getting the GPS pod after few months with the unit. Quite frankly the G3 is a nice option, but not essential piece of equipment.

Bats said...

Thanks kxux. Budget will depend on which one (t6c or RS800CX)is the cheaper. R-R is important. Won't be doing much transitioning, just doing a 3km time trial, recovery, then go into series of sprints, then back for smaller 1.5km time trial etc. this happens about 3 times a week for next 3 months. If he swaps from jog, then to sprint, then back (as above) will watch pick that up automatically (if so which watch) or does he have to manually push (eg lap 2, run, then lap 3 sprint etc). Any help is good help. cheers

kxux said...


from how you describe the workout I would say that the RS800cx with foot pod is better fit. You can actually program workout that monitors if you already ran 3k, then you can program time, distance or HR based recovery and then resume other phase. With T6c you would not be able to setup exercise like that. It is fairly limited in the programmed exercises to one warm-up interval and series of equal int1/int2 that can repeat as many times as you wish. There is no cool down interval. With RS800cx (or even the RS800 which can be still found at cheaper price) you get very flexible programming of exercises. I usually limit my use of T6c to less structured sessions - something like 15 min warm-up, then repeat 30 second pickups with 2:30 recoveries, and 10 minutes cool down. But if I go out and have something more structured like this past weekend - 20 min at long run pace, 20 minutes at over-threshold pace, 10 min at threshold pace and 10 minutes at sub-threshold - this is hard to program in T6c. You would need to remember what you are doing. And that can be challenging especially in some harder runs. When I'm doing track workout it is not unusual for me to do one extra repeat because I miscount the laps. But maybe it is just me who needs more guidance...

Bats said...

Thanks. You're help has been great. He trained last night with a guy who has RS800CX and this guy raved about it, so mind made up. Cheers

kxux said...


good to hear. I'm sure he will enjoy the new watch.


Gabriel Hill said...

Hello, great review. I am a trail runner. can you comment on the accuracy of the watches when running lots of elevation and occasionally climbing very steep trails? i'm particularly concerned with the accuracy of the altimeter and cumulative elevation gain.
I've read the Polar can lose accuaracy when it gets wet or sweaty due to the location of the barometer/holes?? any comments or experiences appreciated.

festerwolf said...

This was a great review, and made me decide to go with the Polar RS800cx. One problem, though, is that I am a Mac user, and I ended up with the IrDA USB 2.0 adapter that won't work with iSmartTrain. So I ordered Parallels in order to run a windows environment on my Mac. I think somewhere you said this is what you do--is this complicated to set up, and can you give me any tips? thanks, Leslie

kxux said...


I do not do much trail running, but the area where I live has quite bit of hills. As far as I can say the altimeter performs well. It may be little off in case of large change in air pressure (it uses barometric pressure to determine altitude changes). This could be seen on long run that you start in overcast and over the course of 1-2 hours the sun comes out and the weather gets nice. You will see this especially if you run loops on the same course - some hills may get bigger or smaller on subsequent loops as the weather changes. Still barometric pressure based altimeters have better performance than GPS based altimeters. When I run with Garmin 310XT I usually end up using WKO+ to correct the altitude profile.

festerwolf: I do use Parallels with Windows XP on Mac when I travel. The installation is fairly easy - when you get Windows setup you install the drivers and PPT5 just as on regular PC. Once you do that the IR stick when connected to Mac needs to be "connected" to Parallels (you will get prompted) and then everything should work just fine. I do not recall any issues in getting this working on the last version of Parallels. That reminds me that I need to get a new license for the upgraded version. During the normal weeks when I do not travel I use PC with XP so I have not used the Parallels version in about 3 weeks.

Anonymous said...

Great review.
Over all, at this time of the year, what would you recomend more for a triathlete, polar RS800CX, suunto T6c or garmin 310XT??
I haved used a Polar RS300 for two years now, and had no problems with it. I used it for many olimpics, 1/2 ironmans and a complete ironman.
I been thinking on buying a new HRM, but still not sure on what to buy. All around what would be your last final choice, or what would you consider for it??

kxux said...


since you are familiar with Polar and their menu structure the RS800cx sounds like a good option for you. I broke down the differences in many discussions here - it basically comes down to your needs and your style. I have all three and use mostly RS800cx or T6c. I use 310xt as secondary watch mostly for GPS functions. If I had to characterize each watch with single sentence I would go somethings like this:

RS800cx - the most configurable and versatile HRM on the market at this time (could be complex for some people)

T6c - simple to setup and use, EPOC/TE based training which can be hard to understand at first; great watch though somewhat limited compared to Polar

310xt - great GPS units with OK HR functions, not useful as watch

My ultimate HRM is RS800cx closely followed by T6c. Garmin is my secondary unit and I never used it in tri race. For some reason I do not have confidence in it - hard to explain.

nicsi said...

Thanks for your review.
I'm thinking pf buying on of these, but cant decide which... )-:
I already have a HR watch, but I want a watch for pacing my running.
I have 3 Qs that might help me to decide:

(1) Can you please compare how "readable" the screens during workout ?
It looks from the pictures that the font of letters on RS800CX is smaller and thinner than Suunto, am I correct ?

(2) In the comments for your post http://runtotri.blogspot.com/2009/04/suunto-gps-pod-second-try.html, you've said that foot\stride pod is better for pacing than gps. Do u still think like that ?

(3) For "pace", as the major factor, which combination do you recommend:
a) RS800CX + stride pod
b) RS800CX + gps pod
c) T6 + foot pod
d) TD + gps pod

Thanks a lot for your help,

festerwolf said...

I have the Polar 800CX with both the GPS and the foot pod. It's ok, but I'm actually thinking of getting the Garmin 405 now because it seems more streamlined and integrated. The GPS is really bulky with the Polar--you have to wear it on your upper arm, and it's quite big. And you can't use it simultaneously with the foot pod--it's either/or. I do like the cadence/stride measurement feature on the footpod, but ended up getting the GPS acessory too because the time/distance was not quite accurate with the footpod. All the runners in my local club have the Garmin 405 and swear by it, and it does seem like a lot less hassle than the Polar . . .

kxux said...


Yeah I know the dilemma of choosing the perfect watch ;-). Unfortunately there is no perfect watch. But some may be better for what you do than others.

(1) Readability of the display is good on both units. But I have good vision so it may be different if your vision if not great. While Suunto has bolder font than Polar I would not say there is a clear winner - especially considering that Suunto has limit of 3 data fields whereas Polar has ability to show graphs and on some screens may provide additional details - like count down of the intervals, HR zone, etc. I would say that Polar has better ability to show data, Suunto is simpler and has less options.

(2) I still believe that foot pod is better at showing accurate pace. I do use it also with my GPS units from Garmin (405 and 310xt) as source of pacing data. For distance the GPS is more accurate. Foot pod has one disadvantage if you switch between shoes and terrains - you need to adjust calibration factor if you want to get accurate pace data. I must admit that over the past year or so I did migrate to GPS based units for the convenience of calibrating the units. E.g. no need to calibrate before the run. Still in race conditions I will rely on foot pod rather than on GPS to see my immediate pace. I do not bother to get too accurate - 10-15s per mile difference in pace does not matter much. I usually look at the watch when my RPE is out of whack and I want to make sure I'm not going too hard.

(3) For accurate pacing I would recommend any unit with foot pod. If you also want GPS then with

* RS800cx you can use S3 and G3 at the same time. RS800cx will take pace/distance from the S3 and GPS location data from G3 (

* T6c/d - don't bother with their GPS sensor it sucks for immediate pace. I'm not alone in saying this. Stick with Food pod only.

* If you value GPS more than foot pod look at Garmin. They are the best GPS unit out there. But their HR and calorie computation isn't the best. Luckily they partnered with FirstBeat some time ago and in their newer units they have more accurate algorithms for calorie consumption (similar to the ones Suunto uses).

Again I do not know your needs, training patterns so I do not make clean cut recommendations. In my case I tend to stick with Polar for training - more complex sessions are very easy to program (also Garmin is good in this regard) and for racing I want simplicity and use Suunto.

kxux said...


Just one correction - you can use foot pod and GPS pod with RS800cx at the same time. If you do that the S3 will be used for pace/cadence/distance and G3 for location data.

As for Garmin 405 - good unit that I use on some runs. Very low maintenance unit and fairly easy to use. There are few things that prevent me from recommending it to triathletes - biggest one being that it is not rated for swimming. I hope Garmin can one day develop unit like 310xt that is actually a watch.

Anonymous said...

kxux and festerwolf,

Thanks a lot for your help and valuable comments.
much appreciated.

nicsi said...

kxux and festerwolf,

Thanks a lot for your help and valuable comments.
much appreciated.

festerwolf said...

kxux, thanks for the correction on the use of the GPS/footpod features on the RS800CX! I had read somewhere you couldn't use them together, but after your comment I did, and it worked great! The GPS is still a little bulky on the upper arm, and needs to be adjusted during long runs, but together you do get a great deal of information. I especially like to see the cadence with pace as I'm running, and to get an accurate distance. Thanks!

nicsi said...

you wrote, regarding using G3 and S3 together:
"I especially like to see the cadence with pace as I'm running, and to get an __accurate distance__."
As far as I understood from kxux,
and also as explained here:


The distance is always from S3, so I don't understand your comment regarding "accurate distance".
Can you please explain ?

Jay in SF said...

kxux and festerwolf,

I'm normally a Polar user but switched over to the Garmin 405cx earlier this year because I was doing a lot of traveling. I liked not having to carry my footpod, gps, etc and really liked that the 405cx was basically an all-in-one unit. It was nice to be able to download my running routes from all of my travels and look at them on Google Earth and say, "I've been there!" The main downside to the 405cx is definitely the battery though because after about four or five hours of workouts, it needs to be recharged. (Mind you, if you're doing a marathon distance run or a century, you can actually charge it on the fly, but why deal with the hassle of carrying a battery pack and charging clip?)

Now that I'm done with all of my travels, guess what? I'm back to using my Polar s810i and using Firstbeat Athlete to monitor my progress (seems to work better for me than Polar OwnOptimizer). The Garmin novelty eventually wore off after a few months. Though I still use the 405cx when I do runs where I want to know the exact distance and look at the route, but for the moment, nothing beats Polar for training analysis.

Now if I can figure out how to properly mount the S3 foot pod on my Vibram Five Fingers, then I'd definitely want to get my hands on a RS800cx!

festerwolf said...

Jay in SF, that's the thing! Although the Garmin maps are much nicer, there is the battery issue. The Polar analysis is more detailed but harder to read/navigate. I wish someone would make a watch that is good at both! Too often now I find myself wearing both the Polar and the Garmin, which is silly . . .

kxux said...

Jay in SF:

I completely agree with you on the Garmin 405 - it is great runners watch with battery that sucks for anything longer. Going a week without charger is a pain. Luckily the 310xt does not suffer from the battery issues, but unfortunately it is not a watch, but a brick you carry on your arm. Fried of mine was about to swim with it in a tri and decided against it after I asked him how he plans to get out of his wetsuit with that brick on his arm. It probably works well with sleeveless wetsuit, but pulling it through the sleeve can mess-up the data (or you have to remember to lock the keys).

I got also tired of monitoring my R-R data in FBA - I did not see that it was giving me much in addition to what I'm already getting from looking at my TSS scores in WKO+ and knowing a little about how I feel.

In the past few months I have been relying on RPE, HR and on the bike on my power meter to dial in the power output. I must admit that my running has been limited to pool runs and measuring HR in the pool is a challenge to say the least. Luckily my old and beaten up S625X still works and measures my HR just fine.

I guess what I'm trying to get to is that there are many ways to work on your improvement and everyone needs to find what works for them. No unique formula exists. While few years or even just months ago I would swear by numbers and calibrate my foot pod couple times a month lately I have been pretty laid back and rely on my feel. I hope my coach reads this because we have been working on this quite a bit. Even this weekend during the race I went by feel though I kept glancing at my power data from time to time to confirm. But I did not ease up when I saw that I push over 400W up the hill for few minutes. I felt like I can do it and it worked out. The worse thing that can happen is that you blow up and have to take it easy for the rest of the race. No big deal ;-).

Jay in SF said...


Sometimes simpler is just better. Perhaps we've gotten to the point where the HRM is no longer a teacher, but a guide. Our HRMs taught us how to listen to our bodies. We know now how our bodies feel like when we've done too much, or too little.

Case in point: Yesterday I did a martial arts demo at a festival. My s810i told me that I'd only burned about 170 calories over 17 minutes (8 minutes practice and 9 minutes for the actual demo). But with the adrenaline flowing, it took a full 20 minutes for my entire body to come back down to a normal level. I ate way too much after the festival (I track calories too) and showed absolutely no weight gain this morning. Polar Optimizer would say I'm recovered. FBA is telling me to rest today (which is interesting). And my body too is telling me that I need to rest because I can feel the soreness in every part of my body and I know that if I go for a five miler today, my heart rate is going to skyrocket and I'll be too sore to do my long run tomorrow.


I hope one day Garmin comes out with a watch that does R-R recording for use in FBA. But until then, I'll stick with my s810i because I can run, swim, and do almost anything with it.


Jay in SF said...


Forgot to ask... When you're wearing both HRM, do you get any cross-talk between the two? And are you getting the same reading on both watches? I get weird looks when I run because I'm looking at both watches - thankfully I turned off the zone alarm on both otherwise I'd be in real trouble - plus my Vibram Five Fingers are very hard to miss. ;-)


festerwolf said...

Jay, no, I haven't had any cross-talk. That's funny you worry about people looking askance at the two watches--I have worried it does seem a bit excessive/obsessive (it is)! I haven't tried the Vibrams yet (one of my friends swears by them, and always wears them to class at the university where we teach), but I did just get some Newtons. Definitely takes some getting used to.

Jay in SF said...


After so many running injuries (plantar fasciitis, runners knee, IT band), I decided to give the VFFs a try. They work for me, though I got a little greedy recently and did way too much weekly mileage. I'm currently sidelined with some pain in the ball of the foot area. But, I hope to be back and running in my VFFs in a few weeks. Kinda sad that I'll miss a half marathon next weekend, but that's okay. Newtons are nice! Have you looked into Chirunning? Some of my coworkers have done it and it's alleviated some of their running injuries.

Jay in SF said...


After about a year of debating which one I should get and hanging out on the Polar and Suunto Forums, using Firstbeat Athlete with my s810i, and checking out polarpersonaltrainer.com and movescount.com, I finally decided which one to get... The rs800cx with S3 and G3!

I think a lot of it came down to the data analysis. I'm an analyst by trade, so I like seeing a lot of information.

I researched the EPOC and TE, and while I find the EPOC useful for recovery -- more-so than OwnOptimizer -- I didn't think that real-time TE on the watch would help me. The only other thing that the T6c initially had over the rs800cx was the memory belt. I like to swim, though have no ambitions to do a Tri any time soon. I also do martial arts and wearing a watch on your wrist in class isn't allowed. But since I need feedback immediately after, or during, those activities, I just use my s810i and stick my watch in my uniform jacket where it won't get squashed.

I'm primarily a runner though, so the rs800cx will get a lot of use on the roads, on trails, and for the occasional cycling.

One of the other things that helped finalize my decision is that I like how Polar has set up its community. I'm finding one of the challenges on polarpersonaltrainer.com a lot of fun. It's very motivational and my fellow competitors have been friendly. Movescount.com doesn't have challenges like that.

Even though Polar hasn't jumped on the ANT+ bandwagon like Suunto and doesn't have automatic switching of pods or -- compared to my Garmin 405cx -- is not an all-in-one unit, the rs800cx just seems to do MORE...in terms of sessions and their variability. And that flexibility and variability, for me, means being able to use it far into the future.

Thanks, Jan, not just for the review here but for your other posts on the Polar and Suunto Forums. Maybe I'll see you in one of the polarpersonaltrainer challenges one day!


Stu said...


First, thanks for this great review and all of the great information on your site. I've been reading it for the last few months on and off. It's really been valuable in helping me make some decisions about getting back into training.

One of those decisions was to pick up an RS800CX last Friday, which I did. I got the MultiSport package with the G3 GPS sensor. I plan on picking up an S3 stride sensor as well. No bike right now, so no bike sensors.

I have a quick question about using the G3 and S3 together. First, some context. Above you mention that Polar saves the log files as text files, and you've copy/pasted information between those files before (specifically you talk about merging data from the CS600 and the RS800CX). Separately, in your in-depth review of the RS800CX you provide a screenshot of the G3 data in Google Earth that shows that if you click on a lap marker a bunch of HRM details about that lap appear in Google Earth. Finally, I know that if you use the S3 and G3 together, all pace, cadence, distance, etc. is collected through the S3 and the G3 merely provides route/location data.

So, given all that, if you use the S3 and G3 together and then export the .gpx to Google Earth, do you still get all the pace/distance/cadence/HRM data on those lap markers? Or are they empty because that data wasn't collected by the G3? If they are empty, is there a way to edit the log file and/or .gpx file to combine the data from the S3 sensor and the G3 sensor? I'd really like to use the S3 sensor, particularly for cadence, but I'd also like the ability to view that data in Google Earth along with route information.

Not sure if you've tried this or not, but if you have and/or just know, I'd really appreciate hearing about your experience trying it. Thanks!!!

Marius said...


I have just started my quest/search for a new watch to use in multisports and stumbeled over your artical here. Must say it was a good one and gave much needed info, but still I am a bit unsre what to buy.
So maybe if I post some of the sports I do and needs, maybe you can help me out?

Sports I do/train;
- Biking (MTB)
- Running
- Crosscountry skiing (winter)
- Downhills skiing (mostly powder skiing)

Needs for all the sports;
- Distance
- Speed
- "Locationd"/GPS tracing
- Altimeter (how many meter of hights have I skiid down or biked or run)

I normaly to all the sports sepratly, but I am playing with the thought of staring on triathlon within a year or two.
But I would like when I am running to know my speed, distance and where I have been/where I am (gps).
Same when I am biking and doing crosscountry skiing. And ofcourse my HR.
When I go downhillskiing, am I not intrested in HR, speed, disdance and so on, only the hightmeeters (bad translation from me here now) I have/had, but can happen I also wanna do the others things too when I walk to the top of the monatins.

As you understand, I do lots of different sports and a wied need for my use and hope to get them all satisfiec in one watch.

So Which watch do you recomend me then? Have been looking at Polar, Garmin, Suunto and so on but I cant find out which is the best for my needs.

Hope to hear from you soon, and maybe you can email me some recomendations?

Hope you hear from you soon.


qBot said...

Is it possible to create a triathlon workout plan using any of the polar software? As far as I understand, the polarpersonaltrainer.com can only create either running or cycling workout plans, but not both at the same time winch very disappointing. Or it is possible to create brick workouts at least?

My concern is that I find polar software useless for a beginner like me: I'm not a couch, so I do need help making a workout plan. And it goes fine if I only need either running or cycling plan, but what if want to do both or specifically a triathlon! In spite of an upcoming RCX5 release which is aimed at resolving all the triathlon related issues I find this lack of planning support quite disappointing.

dress pant said...

for me one more point of clarification - the T6c and RS800cx are almost the same size. Polar is not bigger that T6c.curved design is more smaller.

CH4:D said...

Not exactly the review I was looking for but it gave me a general idea of the respective brands mentioned.

Thanks for this!

Greg said...

Hi, great site and very useful.
I just have two simple questions.
1/. The Suunto and Polarheart rate monitors don't work in waterand I assume this is also true for the GPS devices, but are they waterproof? That is, can you keep them on if go from running or cycling to swimming and then back to running or cycling or do they have to come off for the swim?

2/. Can the batteries for both the T6c/d and the Polar RS800cx be changed by the user (I pretty sure I;ve read this is done by the user for the Suunto watches) and are they still water proof if you do it yourself?

kxux said...

Hi Greg,

1/. The Suunto and Polarheart rate monitors don't work in waterand I assume this is also true for the GPS devices, but are they waterproof? That is, can you keep them on if go from running or cycling to swimming and then back to running or cycling or do they have to come off for the swim?

J: I swam with all my HR monitors with no problems. The T6c/d, Garmin and RS800cx do not give you HR while in the water, but they work fine once you get out of the water. Never had any issues.

2/. Can the batteries for both the T6c/d and the Polar RS800cx be changed by the user (I pretty sure I;ve read this is done by the user for the Suunto watches) and are they still water proof if you do it yourself?

J: Yes. I did change them all myself. Just be sure to screw the cover back correctly and you may also want to clean a little bit the rubber seal. Otherwise it is very easy.