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Polar S625X vs Garmin Forerunner
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There's actually a 9 sec delay, not 10, but who's counting. This occurs when there is a significant change in speed such as starting from a standstill. The pod (used by many other HRM vendors) has to take extra time to integrate the rapidly changing accelerations from the 6 accelerometers in the pod. Once you get to a steady pace, there is only a 2-3 sec delay.
BTW this long delay can add more than 10 meters to your distance so you should strive for steady pace running as much as possible. Polar even has added a blurb about steady running on their website.
This delay also impacts how you calibrate your pod. You should calibrate from a running start and run past the end lap point slightly. Also you should use longer distances than specified by Polar. Again see Willem's document or Yahoo's forum for more information. After reading this you'll also be able to handle speed intervals more accurately.
In spite of these and other bugs, most S625x users are very happy and find it a very useful tool for their training. All GPS and Pods systems have their quirks and errors.
I have done 3 races with my watch and pod. I was satisfied with the distance accuracy for each race(96.7% 10k,98.2% 10k and 99.8% marathon).
A friend ahs teh 625 and is a professional trianer and gadget fna and after several weeks is still struggling to wokr out all the functions and says it is way too complicated.
Both the 301 and 625 over the freedom to just run without being tied to a measured course. And both give decent distance accuracy.
My understanding is that the 301 has serious issues with HR measurements and real-time pace readings. At least these are the complaints I'm seeing at the Garmin forums. The 625 does well in both categories. I also think PPP SW is superior to what Garmin has.
However, it would be fun to map out some of my routes with a 301 or 201, but for my serious training measurements I'll stick the 625.
thanks for the e-mail. Must confess I am a little disappointed that you think the problem may be with the watch.
Forgive me if this is a stupid question, but how can the data be stored 'correctly' in the watch record file, then not transfer properly?
On another 625 issue altogether, can anyone help with this?
I run with a friend and until recently we both wore S120 HRMs without any problem from interference. I understand that the S120 is not coded.
Since I have started training with the S625 her S120 is not reading her heart rate properly. Is there anything we can do about this?
I may not have stated the problem clearly and I will therefore have another go.
PPPSW:
Curve: Duration 50:20:00 - Distance 5.9
Listing: Duration 50:15:00 - Distance 5.95
LapTimes/Marker: Duration 51:19:6 - Distance 6.02
WATCH:
Duration 51:19 - Distance 6.0
The Lap times/Marker info from the PPPSW and the info from the watch, which is identical, are correct. The others are not.
I have had a few Polar products and the last one (have forgotten the model) had a sonic link which enabled me to download data from the watch to the 'PC Coach' software. It was excellent and always reliable. My previous SDM was the Nike Triax 100 which lasted 2.1/2 years and indicated the pace on the watch at exactly the same time that is was sensed at the foot pod.
I have paid a lot of money for the S625X and expected it to work properly. Fancy having a temperature sensor that measures your wrist temperature!!!
Sounds like the S625x is not the watch for you. Polar is claiming an accuracy of 97% and you're unhappy with 98%. Imagine telling a runner in 1970 that he could wear a watch and run 6 miles on any arbitrary path and it will measure it to within 160 yards. I think he may have been very excited about that. And then tell the runner he'll be able see his HR and elevation at 5 sec intervals along with his time, speed and distances.
I don't know why your Curve and Listing distances differ, but you need to be careful about comparing PPPSW sample distances with lap distances. They will never be equal but only approximates of each other.
Lap distances are calculated internally to the watch and uses 2 sec samples(approximately) for computing distances. These computed lapdistances are later sent to the PPPSW as is. However, the sample point distances are calculated by the PPPSW from the velocities at the sample times you have chosen(5,15,60 seconds) so the curve and listing distances will be more coarse. If you rerun your 10K but use 60 second samples I think you'll see a larger discrepancy.
I would love to have Polar store velocities at 1 sec intervals so PPPSW has a chance to be more accurate. But they made a choice between this and the number of files than can store in its memory. Possibly when they can get more memory on the watch this will happen.
The S625X is used by runners, cyclists, and swimmers. The temperature is accurate for cyclists as the watch is mounted on the frame. I guess Polar could have hid the temperature functionality from the runners so they wouldn't know about it and be frustrated.
If I run a 10K race I would expect the overall time to be accurate, I am not so worried about the distance. Reducing the result time by a minute as highlighted seems odd to me anyway.
Now I see your problem. I'll send you me email address. If you care to send me the corresponding hrm file, I'll attempt to resolve the problem if I'm able to. I have some questions:
(1) Did you start the recording from a standstill or when you foot crossed the starting line?
(1) Did you use autolap?
(2) Did you use manual laps?
(3) How did you stop the recording at the end of the race? (lap button then stop or just stop)
If you haven't done so already, my first suggestion would be to get the software update from the Polar website.
(www.polar.fi) - go to the product, then "support and downloads" and you should find the update on the right hand side.
Since the S625X came out last year, there have been at least 3 updates - and things are a LOT better than they were.
Also, check that your sample rate is set to 5 seconds.
The thing to remember is that the watch is right - the software is just doing the best it can with the information it gets - the watch has more information than the software and so has the numbers to trust - if you find that you have a big difference.
I think the 625 is excellent. It does exactly what it says it will.
Oh, and XL-man - I don't think there is anything you can do to stop your HRM bu**ering up your mates - except run slightly further apart!
OMM
Some answers for you:
1. I started the watch at the sound of the gun but was stationary until the runners in front got underway.
Your second 1. and 2. I activated the red lap button at every K sign to get my split times. One was missed.
3. Just stop. The watch time was very close to my recorded finish time.
Is the time in the "time" box on the graph screen right?
When I first got mine i had a problem where a certain run I did seem to increase in distance by 100m every time I did it.
I emailed Polar who suggested that the pod might be loose.
Sure enough, if I put it so that the top of the pod is at the top of my laces, and make sure I lace it in so there is no 'wiggle' side to side, then I don't get that problem. It's amazing how much difference it can make.
Funny that the time box is wrong on the graph screen - I've never had that.
Do you have Polars email address? I filled in a form on their web page, having taken about 30 minutes to register! They have not responded.
'Is the calibration default setting for foot pod on the watch 1000?
If not does anyone know what it is?
Many thanks in advance!'
Cheers guys
The loss of data on transfer through the IR interface has been sorted by the latest PPS update. Thanks for your assistance.
:0)
Great! Polar should place a reminder tag on their boxes to insure new users to upgrade to the latest PPPSW.
ORR - the email address is helpdesk@polar.fi
Many Thanks
For me that's a huge gain and means I can analyse my training with much more confidence than before. The other huge improvement is having a real time pace measurement. This is pretty hopeless on the F201 but - as far as I can see - far more accurate on the S625X. Finally, the desktop software is better with the S625X. I find the workout graphs are really useful.
What do I miss about the GPS system? Well, it's nice being able to work with maps. And the training "buddy" is pretty inspired. There's no reason in principle (apart from the computing capacity and memory of the watch) why a footpod based system shouldn't be able to do those things too.
Ah well, I guess we'll have to wait a little longer for the perfect gadget.
I've had mine for 30 weeks now and I've never lost my interest with it. I do believe all the HRM manufacturers are in their infancy stages and we will see very cool things in the future. The 625x is Polar's first attempt at the pod, so we'll see major improvements as their experience increases. Same thing with Garmin and the heart strap.
I'm hoping each manufacturer is looking at the features of the others. I would sure like to see Polar with an audio announcement feature similar to MP3Run ( I haven't heard it, but I could imagine it to be very useful).
I would also like to see a GPS mapping accessary that could work with Polar. To maintain the accuracy and dependability, the pace and distance would still come from the pod, but the gps mapping coordinates would be received from a GPS unit and stored in the same file which could then be downloaded to PPPSW. I would love to see where I run, but don't want to depend on satelite signals for my training and race data.
I agree with all of that - and it's good that you're still enthused by the 625X. Is GPS capability strictly necessary for mapping? I'd have thought the data from the foot pod ought to be enough to calculate position as well as distance and speed. (Obviously you'd have to enter some reference co-ordinates - eg for the start of your racce - if you wanted absolute position).
Interesting idea. But in order for you idea to work, you would get an accurate orientation from electronic compass on the watch. Suppose you ran in a straight line for 10 miles and wanted to be within 50 feet of the center of the road. At the start of the run you would have to know your orientation to within .05 degrees which is probably pretty difficult for a compass.
Also the problem would be that the errors in the calculated x,y coordinates are accumulating to an unacceptable large values.
The advantage of GPS is that the errors are not cumulative.
Interesting thoughts. Without knowing anything about how the foot pod works, I've been assuming that it measures acceleration as a 3-D vector, from which the watch ought to be able to calculate the direction in which you're running without a separate compass.
But your argument about accumulated error is obviously absolutely right.
been a while since I posted here, but as Riverman says, it has become a useful forum.
I have a question which I have posted on the Yahoo group, but I'm yet to receive any feedback.
I've had my 625x over a month now and it has quickly become invaluable.
I have noticed a discrepancy between the total distance run as recorded on the watch, and the sum of the distances run as given in the View/Laps tables on the PC.
Last Sunday I ran a distance given as 6.91 miles at the last 5sec sample point. When I added up the total of the lap distances, automatically set for 0.5 miles, the total was over 8 miles !
Any ideas gratefully received.
'Lap distances are calculated internally to the watch and uses 2 sec samples(approximately) for computing distances. These computed lapdistances are later sent to the PPPSW as is. However, the sample point distances are calculated by the PPPSW from the velocities at the sample times you have chosen(5,15,60 seconds) so the curve and listing distances will be more coarse. If you rerun your 10K but use 60 second samples I think you'll see a larger discrepancy.'
OMM, if I have understood this correctly, then the total of the laps is correct and the samples are underestimating! Is that th ecase, or am I just hopelessly confused?
I'm puzzled by the the large discrepancy you're seeing. I'm seeing very little difference between the two. The following are the summed lapdistances and last sampled distance for my previous runs.
LastSample LapTotal %Diff
(mi) (mi)
5.529 5.532 .05%
4.249 4.263 .33%
14.083 14.064 .14%
6.802 6.818 .23%
These were slow steady runs with autolapping set to 1mi and sample time at 5sec. Your difference was about 13%.
I reviewed Willem's document trying to find the answer to your question about lap distance accurancy vs sampled distances. It's worth reading and is much better than getting it second hand from me.
You'll find a link to his document in the link section at Yahoo's forum.
He claims there are conditions where accumulated lapdistances are more accurate and others conditions where final sample times are. Hows that for a straight forward answer.
He states that each lap interval will add an extra 10-40 meters to the total and so lap intervals should be large to minimize this effect. He calculates that a lap interval of 800m would yield an accuracy of 97%.
After rereading it, I should correct a previous post. Willem proves that PPPSW does not use the lapdata from the watch even though it's sent to it. It recalculates the lap distances from the sample distances.