October 4, 2005 at 8:22 pm #4595
Are those things any good for training – I want to be sure that my distances are accurate. They are so expensive – so at this time I am hoping to err on the side of running farther rather than short. Plus it would be great to track my paces through some long runs so that I can disect my tendencies.
Any advice or suggestions? Any one looking to sell one off cheap?
October 4, 2005 at 9:05 pm #19481
I had a Forerunner 201 for about a year before I “lost” it this summer. Turns out it was found and returned, but not before I seized the opportunity to upgrade to a 301 complete with heart monitor. I share this to demonstrate how how much I love and have come dependent upon my Forerunner(s).
I enjoy the simultaneous calculation of distance, pace (either in minutes per mile or miles per hour, depending on if you’re using it running or biking) and route mapping. You can pre-program interval workouts and even set an imaginary competitor at a pace for you to beat.
My Forerunner doubles as a cyclometer, snapping into handlebar mounts I’ve placed on both my road and mountain bikes.
The Forerunner is as accurate as GPS technology can be, I suspect. I wore mine for Al’s Run, for instance, and had trouble getting it to lock in satellite signals before the start because of Milwaukee’s tall buildings downtown. (A “weak signal” message will also flash during the course of a run if you find yourself under tree cover for too long but it will recalibrate once you’re in the clear again.) Ultimately my Forerunner measured the Al’s course as 4.97 miles instead of 5.
I’ve come to trust the device to the extent that I can’t remember the last time I used the car’s odometer to figure out the distance of a running route.
I justified buying the newer and most expensive 301 because I wanted a heart monitor and didn’t want to have to wear another watch. The much more detailed logbook capabilities of the newer model is downloadable to my computer, showing maps of the routes and elevation I’ve run. I haven’t figured out how yet, but apparently there is software available that allows me to do the reverse: map a course and download it to the Forerunner. Then, when I run that route which could be in another part of the country if I’m traveling, it will alert me when I need to turn left, right ect. That seems useful if I know I’m going to be in unfamiliar territory and don’t want to carry a paper map.
The Forerunner is a luxury item, no doubt. Hardly essential. But I really like being able to glance down at the digital face and instantly see my mileage run, time elapsed, pace and heartrate all at the same time. I can go back through the recorded history and see my mileage by week and workout. I keep a written log, too, but the Forerunner is a very helpful backup.
There’s a lot of debate elsewhere on the Web about the accuracy of these devices, but I’ve found mine to be reliable and consistent over nearly 18 months of use.
October 4, 2005 at 9:09 pm #19482
I’m sorry, Ed, but I gave my Foirerunner 201 to my Luddite brother-in-law. Once he starts using it, I expect he’ll become a convert, too.
October 4, 2005 at 9:22 pm #19483
Just remember that no GPS product can guarantee accuracy beyond what I recall being the 7% error tolerance of the technology used. This means that no GPS product can guarantee more accuracy than saying a route measured as 10 miles is known to be between 9.3 and 10.7 miles. Most people report better results than that when testing the products with known distances but the bottom line is that results can’t be guaranteed. I’ve heard numerous stories of people running certified race courses and claiming that their GPS “proves” the 5k course was 2.9 miles or the 10k course was 6.5 miles or the marathon was 27.6 miles. It’s tough to get across to some of them that GPS is less accurate than the method used to measure and certify a race course.
That said, as a “techie”, I’ve always been curious about them and would love to play around with one but I can’t justify the expense to my frugal self.
If you do get one, make sure you download all the latest firmware updates. A coworker of mine has a Forerunner. He went out on a run from work with it and ran out for 3.5 miles before backtracking for a supposed 4.5 miles. When he got home and tried to figure out what happened, he realized that he went straight up a half mile in 3 seconds and back down a half mile in 5 seconds. I guess some firmware update he got took care of the altitude miscalculation problem.
October 4, 2005 at 10:06 pm #19484
I don’t know anything about the GPS products. I just bought an odometer ($20) for my bike and verified the reading on a track. Granted it means I have to find time to bike my routes in order to measure them, but since I usually run on a lot of the same roads, it’s not a huge task. Sometimes remembering where the mile markers are can be hard. I’ll either make notes on paper or even spray paint the path.
October 4, 2005 at 11:10 pm #19485
The accuracy of gps is far better than 7% (under normal conditions).
The US military reserves the right to re-introduce an inaccuracy into commercial gps signals (the gps satelite network is controlled by the US gov).
That was standard practice from the inception of the gps system (the introduction of a ‘random’ factor into the commercial unencoded signals).
The government (under pressure by business advocates) reversed that policy. Since then the gps network sends equally accurate signals (military and commercial) but this can be changed at the discretion of the military (presummably this is done only in the face of national danger).
A great piece of software for use with the Garmin is ‘SportTracks’. Not only is this a great electronic log book (for use with or without a gps watch) but it shows the route superimposed on US Geological Survey maps of the US, on Topoligical maps, or on Satelite photo maps. You can zoom in on your run to the level of seeing the house you ran past!
And you can ‘crroect’ the route with the mouse so if the displayed route takes you through a yard instead of around the corner (as seen on the satelite phote or map) you can drag the ‘line’ with the mouse to the correct location. It automatically recalculates the pace and distance.
A great piece of shareware software!
October 5, 2005 at 12:22 am #19486RandyS wrote:The accuracy of gps is far better than 7% (under normal conditions).
You might want to double check your manual. Even without the introduced inaccuracy, there is inaccuracy simply due to the technology.
Monday night marked the removal of selective availability (SA), a process that altered the signals received by civilian GPS users, making positioning accurate only to within 100 metres, while the military still had access to the undegraded signal accurate to within 20 or 30 metres.
Before 2000, any given reading could have been as much as 100 meters off. While the intentional margin of error was removed, the technology is still only accurate to within 20-30 meters. This, along with tangential issues when turning corners and other such issues involved with movement, is where the 7% margin of error comes in. While it is unlikely that a person would see a measurement that is a full 7% off, it is not impossible. If you read your GPS manual closely, as I have a few different manuals, you will find somewhere that they give you a margin of error. Of the ones I read, the margin of error given was between 7% and 10%.
October 5, 2005 at 12:44 am #19487
The spec page in my Garmin 201 manual claims gps accuracy of less than 15 meters. For the reasons I use it this is accurate enough.
October 5, 2005 at 12:56 am #19488
… and the specs for my Forerunner 301 says the GPS accuracy is within 15 meters,” 95 percent typical.” The footnote to this explains that the device is “subject to accuracy degradation to 100 meters under the U.S. DOD-imposed Selective Availability program (when activated). Accuracy depends on view of sky. 99 percent clear view; 95 percent typical.”
The question I would ask is what alternative technology is there that would measure our running routes more accurately?
October 5, 2005 at 1:07 am #19489RandyS wrote:The spec page in my Garmin 201 manual claims gps accuracy of less than 15 meters. For the reasons I use it this is accurate enough.
Is that 15 meters every reading? That would mean, as I sit here in my living room, it would say I’m in a neighbor’s living room 15 meters away. Multiply that margin of error over many readings over the course of a run and you could potentially get a very significant margin of error in determining distance traveled. Due to the technology, though, the margin of error is less than it could theoretically could be but it’s not as miniscule as some people (like those claiming certified courses are inaccurate) would like to believe. According to the manual available on the Garmin website, you get 95% typical accuracy, which would mean that a route measured as 10 miles would typically be between 9.5 and 10.5 miles. I can’t find a specific error tolerance. It also offers the following disclaimer:
Given GPS limitations, allow for some error in calculations. Train accordingly and with common sense. GPS is to be used as a reference tool.
Based on my experiences, such as a coworker telling me that my route that I estimated to be 8.1 miles came out to 8.1, 8.2, and 8.0 miles on his Forerunner on three different days, I personally have trouble justifying the cost of one. Of course, that’s just me.
October 5, 2005 at 1:12 am #19490jtpaten wrote:The question I would ask is what alternative technology is there that would measure our running routes more accurately?
Race course certification requires a carefully calibrated bike odometer. Track measurements are usually made with measuring wheels. If you are looking for precise accuracy, that would be more precise than GPS. If you are not looking for precise accuracy, I can tell you that any 10 mile route that I estimate by time and effort is well within a 9.5-10.5 mile range on the first run and much closer within 3-5 runs.
The question I would have to ask, though, is how important are precise measurements for training routes?
October 5, 2005 at 1:19 am #19491
The 95% does not relate to distance accuracy. It means that 95% of the reading will be accurate to under 15 meters. That cannot be translated to mean a given routes measurement will be off by +/- 5%.
In any case I am not saying it is the end all and be all of accuracy. How useful it is, given its accuracy, will depend on how you plan to use it.
To get a reasonably close measure of my training routes, along with splits, without requiring any action on my part makes it worthwhile to me.
October 5, 2005 at 1:34 am #19492RandyS wrote:The 95% does not relate to distance accuracy. It means that 95% of the reading will be accurate to under 15 meters. That cannot be translated to mean a given routes measurement will be off by +/- 5%.
According to Garmin as I quoted above, you should expect error in measurements. I can’t find specific numbers in Garmin’s online manual but I have seen numbers elsewhere, as I have pointed out, that always fell within the 7%-10% range.
Of course, all I’m doing is pointing out that they are not as accurate as some people think. If someone wants one, they should get it. However, there is a lot of false advertising out there about their accuracy. They are not 100% accurate. At best, they are within 95% accuracy most of the time. If that’s good enough for you, great, get one. In fact, get it through RRS and help me pay the expenses for the site. 😉 As for me, though, real world testing has shown that it’s no more accurate than the free method I use now.
October 5, 2005 at 12:41 pm #19493
I have either the 101 or 201….not sure. I don’t use it much unless I’m running a new route. It does very from day to day where it places mile posts. I used it last year a lot and got used to “about” where my mile markers should be. I wheeled the same course this year and all the markers were within 10′ of where I thought they should be. So the GPS on average does a great job.
It does NOT do a good job in any town with even small buildings, a densely wooded forest, or the mountains. Not good at all for these situations. If you have to run under bridges forget it.
I’ve also run certified race courses with it that are in fact “not correct” according to the GPS.
On a side note I actually used the GPS a few times snowmobiling last winter. I had the GPS up to 113 mph a few times. I wonder how many Forerunners have had 113 mph on the display??? 😀
October 5, 2005 at 1:04 pm #19494
That was an amazing wealth of info and discussion – thank you all.
For what I am doing I do not see the expense being worth it at this point.
If I manage to go sub three next fall and feel that I can get faster yet – then maybe – but until then…
October 5, 2005 at 1:41 pm #19495
I am using the foodpod from polar. I have abandoned the hearth rate belt, but still use the pod to log my distances. I think polar claims it is accurate 97% when not calibrated and 99% when calibrated on the same kind of surface of your run. I haven’t calibrated it yet, but the distances I recorded with it, matched with distances I know. And last week a 20k race was exactly 20.0k. It uses a different technology then GPS, but I think it is as accurate as they claim it to be.
I am running on time and turn back after 30, 45 or 60 minutes, and try to get back to my starting position in the same amount of time. Usually I only look afterwards what distance I covered, but the times that I looked at it on the halfway point, it was exactly half (give or take one or two steps) of the distance measured when I returned to starting position.
For logging purpose, (fe. hope to see some improvement in steady state tempo over a long time), it will be more than accurate enough. I will not use its readings to question distance of certified or even non-certified races.
October 5, 2005 at 3:30 pm #19496
Thanks for the info – I will think over all of my options.
October 5, 2005 at 5:43 pm #19497
I bought the 101 for $99 with free shipping, and I’m glad I got it. I like it because I don’t run the same routes very often. We have asphalt bike paths all around the part of town I run in. I run on these paths almost exclusively, but I often change the route on a whim. The Forerunner helps me track my mileage and pace. I also use it for repeats because I don’t run on a track.
October 5, 2005 at 7:30 pm #19498
Ryan, how do you measure your runs? Surely you’re not out there with a measuring wheel or run exclusively on a track. What’s your “free” method?
My Forerunner serves as my bike odometer, which points out its versatility. While you’re fixated on proving it isn’t perfectly accurate (no one in this forum claimed it was, just better than the alternatives), I’m using the device as I run a variety of courses and terrains and utilize other features, such as mapping, elevation charting, interval workout programming ect.
I don’t mean to sound like a shill for Garmin, but its a pretty amazing piece of technology.
October 5, 2005 at 8:21 pm #19499
Quite the discussion! I am the benefactor of another’s “losing” their 201. While I have not used it, I can attest to it’s usefullness. jtpaten and I have run a few marathons together, the former using the 201 and me the sporty $10 watch. I am decent at math and sometimes enjoy calculating times while running, I need to run an 7:30 pace, so I need to arrive at the next mile marker at such a time. It can take one’s mind of the pain.
jtpaten doesn’t have to do this, pace is given constantly. So it may not be 100% or 97% accurate, it’s darn close. Once I do start using the gift, I anticipate becoming addicted, one of the reasons in my slow acceptance of the gift. My sporty watch has been working, why change? One reason is my training, I started running for time and not mileage, run 60 min, not 8 miles. But as we all know, it’s nice to know have far we’ve run. And some days we think we’re doggin’ it and the mileage pace comes out okay or other days the run feels good but we’ve not gone far or fast enough. I could drive my car to measure it, waste of gas!
I suppose I could follow up all my runs with a bike ride, if I were training for a tri that’d be good but sometimes it just isn’t in the training or the legs to do so. I have used computer technology, online maps and a measuring tool.
But what I think will be great about the 201 is the ability it will give me to change my route, hey that’s looks like a nice trail or a not so busy street! And as mentioned before by someone, you can use it anyhwhere, where you may not have a bike or car.
Yes it’s expensive, unless…, it may not be 100% accurate but then again I have not heard of someone officially measuring a course with GPS.
It’s quite simply a damn good training tool for running or any other silent sport!
Chicago here we come!
October 5, 2005 at 9:09 pm #19500jtpaten wrote:Ryan, how do you measure your runs? Surely you’re not out there with a measuring wheel or run exclusively on a track. What’s your “free” method?
Time and effort. Amazingly, this without fail seems to get me within a 2-3% margin of error on my first run over a new route and well within 1% within 3-5 runs. Considering the fact that the body doesn’t know the difference between 10 miles and 10.2 miles, this has always seemed more than accurate enough for training purposes. If I need precise distances, I hit a track where I know the distance has been precisely measured.jtpaten wrote:While you’re fixated on proving it isn’t perfectly accurate (no one in this forum claimed it was, just better than the alternatives)…
I’m not fixated on anything but pointing out flaws in statements I have seen all over the place. I have discussed with a few people the flaws in GPS technology that lead to error after they bought GPS systems being told that they are 99-100% accurate only to find later that they were getting typical readings that were 5-10% off of actual distances. Two of these people said they would not have bought their GPS systems had they known the actual error tolerance ahead of time. I just don’t want more people to pay the big bucks for one of these products under false pretenses of extreme accuracy.jtpaten wrote:I don’t mean to sound like a shill for Garmin, but its a pretty amazing piece of technology.
And I don’t mean to sound like a Garmin hater, I just want people to know that wild claims of 99-100% accuracy that are floating around are impossible given the technology. Maybe occasional measurements will be perfectly accurate but there is no guarantee that all measurements will be, as proven by my coworker who I pointed out above ran the same route 3 times and came up with 3 different distances and another time ran an out and back and supposedly added on a whole mile coming back.
I e-mailed Garmin asking for specifications on distance calculation accuracy but haven’t heard back from them yet. If I do hear back, I’ll be sure to share those specifications.
October 6, 2005 at 11:49 pm #19501
I got a 201 last year at Target. My husband had gotten my a Timex Bodylink for Christmas and I hated it . Too complicated and it would often “quit” halfway through a run. I got the 201 since I saw it and it was much cheaper. I immediately fell in love with its simplicity of use. My husband used it once and immediately when and got one for himself. One if the main reasons we love having one is being able to see how far you have run while running instead of mapping out courses before or after. This is great when doing long distance running on our local rail-to-trail where you can’t drive.
October 7, 2005 at 12:59 pm #19502jtpaten wrote:Ryan, how do you measure your runs? Surely you’re not out there with a measuring wheel or run exclusively on a track. What’s your “free” method?
Why do you have to have measured routes? Do you think your body will know the difference between an 8 mile run and an 8.1 mile run? Do you think your overall development as a runner will be better by running on accurately measured training loops? If you start pushing the pace on your easy days because your concerned with your splits, your development could be worse.
Sure it’s nice to have a few miles marked and check pace every once in awhile. However, for me, knowing my split for every single mile I run would drive me up a wall. Heck, even knowing that ever run is exact would drive me crazy because I’d always be doing the math and calculating my exact pace every day.
October 7, 2005 at 3:12 pm #19503
This discussion has definitely turned me against the expenditure – it is so true that my body will not know the difference ina couple tenths of a mile – I always tack on a little to be sure to cover the distance and not fall short in training.
Zeke – are you coming to Madtown for Jingle Bell?
October 7, 2005 at 4:50 pm #19504Ed 1 wrote:Zeke – are you coming to Madtown for Jingle Bell?
I doubt it. I found out in 2001 that driving 4 hours right before a race doesn’t make for a fast time.
October 7, 2005 at 5:43 pm #19505
Too bad – it would be fun to blast away the other teams –
October 7, 2005 at 6:35 pm #19506Ed 1 wrote:Too bad – it would be fun to blast away the other teams –
Well you don’t need me to do that.
October 7, 2005 at 7:08 pm #19507
yea – but it would be fun to be so deep as to have our top 7 or 8 be able to score 😉
October 7, 2005 at 7:19 pm #19508Ed 1 wrote:yea – but it would be fun to be so deep as to have our top 7 or 8 be able to score 😉
Again, while Zeke would almost surely give us one more person at the very least battling for a scoring spot and while it would of course be great to see him again, I don’t think we need him to do that. Take the Al’s Run team, build a bit on that with either new/returning members or guys stepping up, and we’re there.
October 10, 2005 at 7:48 pm #19509
Well, I finally heard back from Garmin on the accuracy of the units and I promised I would share the response if I got one so I’m holding myself to that promise, even though the easy way out would be to forget the promise and let this fade away. Below is the copy/pasted response I got. The only modification I made was to bold the recommendation for emphasis. In short, this response shows that Garmin doesn’t even recommend using the Forerunner to determine a route’s distance but instead recommends that you rely on more accurate measurements, determine the level of inaccuracy for a given route, then adjust for that inaccuracy.
There are not any specifics about typical accuracy of distance calculations with the Forerunner series units. They are used as a reference tool. Depending on how good your satellite acquisition is at the time you are running and where you are running could affect the accuracy of the distance. I have talked to people who get very accurate information with the Forerunner and others that get inaccurate readings. My recommendation is always to measure the path you are running or use the markings provided and then set your unit up accordingly to assist you in your training. You will be able to find the inaccuracies and be able to adjust for them quite easily if needed.
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