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Course distance measurements
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 2009-08-17 3:26 PM |
Regular 100  Denver |  Subject: Course distance measurementsIn your experience, are courses generally accurately measured? I've done three sprint triathlons so far and at least according to my Garmin 305, the run has been off on all of them! Longmont Triathlon - my GPS showed a length of 3.2. The mile markers were exactly right, all the way through mile marker 3, but then from mile marker 3 to the end was .2 miles intead of .1. Tri the Creek - The mileage was only 2.6! The race director admitted they had the volunteer at the wrong spot in an email. Well, "admitted" is probably not correct, he essentially blamed the volunteer, which I found really annoying. His email contained no apology or anything, just, "the volunteer stood at the wrong place." I felt kind of bad for all these people that were super stoked about their PRs in the run that they had set (and they didn't announce anything or put a note in the results, so if I hadn't had the GPS, I'd have thought I ran a 26 minute 5k, which would have been ridiculously fast for me). Rattlesnake - Came out to 3.01 on the GPS, so just slightly off. This one could have been due to the fact that the run was on a winding sidewalk so if the GPS only took readings every few seconds it would have cut off some corners. That said, it seemed like the turnaround was right at 1.55 miles, but the finish was at a slightly different spot than the start and was maybe just a bit short. (Did anyone else who ran this on Sunday have a GPS, if so how long did it say the run was?) Am I the only one who goes a little nuts with this kind of stuff? I want to be able to compare my 5k times, or at least my pace per mile, but if you go off the results published by the triathlons, it seems like you can't. For example, Rattlesnake's results page says that I ran a 9:20 mile pace, but my calculation was 9:40. That's kind of a big difference. For comparison, the one pure running event I've done since getting the GPS was advertised as a 4 mile run and the GPS said it was 4.01, so essentially right on. I wouldn't care if the courses were 3.2, 2.6, or 3.0 miles as long as that's what they were advertised to be and the results showed them that way so the pace info was accurate. The bike courses have also been off, Tri the Creek was a little short, and Rattlesnake was a little long. That I can understand a bit more since there was more variability in where you rode, how you take corners, and the fact that their hands were a little tied on where the turnarounds were. I'm also a little less concerned about comparing the bike rides between courses. Thoughts? Edited by BobJ123 2009-08-17 3:28 PM |
| 2009-08-17 3:31 PM in reply to: #2353996 |
Resident Curmudgeon 25290  The Road Back Gold member | Subject: RE: Course distance measurements There is no certification of tri course distances as there is for road race distances, so you're going to find discrepancies in nearly every case. If the run bothers you, you don't even want to begin to think about swim courses. Bottom line is that everyone runs the same course, so competitively it doesn't matter. |
| 2009-08-17 3:35 PM in reply to: #2354016 |
| Regular 100 Denver | Subject: RE: Course distance measurements Well, like I said I don't really care what the actual measurement is, as long as they publish what it is instead of just saying, "it's 5k". Swim courses are harder for them to control, since the buoys can move in the wind, but they probably don't bother me because I don't have the gps in the water. heh. |
| 2009-08-17 3:38 PM in reply to: #2353996 |
Veteran 294 Papillion, NE | Subject: RE: Course distance measurements haha No you are not alone. Because I am a very anal person I had to check my distances. Swim was right on as it was in a pool. Bike was 13.2, was supposed to be 15. Run was. 2.8, supposed to be 3. I don't really care but would just like to know so I know what my averages are. MPH times. I don't want to figure off the longer distances if they really aren't accurate. I suppose it makes for a better draw to list them longer. |
| 2009-08-17 3:38 PM in reply to: #2354016 |
Master 1591  San Diego, CA | Subject: RE: Course distance measurements the bear - 2009-08-17 1:31 PM There is no certification of tri course distances as there is for road race distances, so you're going to find discrepancies in nearly every case. If the run bothers you, you don't even want to begin to think about swim courses. Bottom line is that everyone runs the same course, so competitively it doesn't matter. ^^^ I agree, we all run the same course. I've run races where the run courses were short by .5 miles or over by more than a mile or a 500y swim course turning out to be more like 700y+. Yeah, they throw off pacing but we're all in the same boat. |
| 2009-08-17 3:42 PM in reply to: #2353996 |
Master 1826 | Subject: RE: Course distance measurements you also cannot trust the GPS to be accurate for the measurement. It will have an accuracy of between 10-30ft per point so depending on what building, trees etc are around.. you distance will change. You looking at about a 2-5% accuracy rate Tri course not measured, GPS not 100% .. so it is what it is |
| 2009-08-17 3:43 PM in reply to: #2353996 |
| 354 | Subject: RE: Course distance measurements I don't have any experience-doing my first tri this weekend. I did, however, talk to the race director for my sprint tri last week -she mentioned the race was just under the 5K distance-I was glad to know that, but a little disappointed, too, that it wasn't the distance that the race site said it was going to be. She also said the race isn't sanctioned-not sure if that makes a difference. |
| 2009-08-17 3:44 PM in reply to: #2354037 |
| Regular 100 Denver | Subject: RE: Course distance measurements jezzieswims - 2009-08-17 2:38 PM the bear - 2009-08-17 1:31 PM There is no certification of tri course distances as there is for road race distances, so you're going to find discrepancies in nearly every case. If the run bothers you, you don't even want to begin to think about swim courses. Bottom line is that everyone runs the same course, so competitively it doesn't matter. ^^^ I agree, we all run the same course. I've run races where the run courses were short by .5 miles or over by more than a mile or a 500y swim course turning out to be more like 700y+. Yeah, they throw off pacing but we're all in the same boat. Yeah, but I'm slow and I'm really just competing against myself...well until I get passed by someone I think I can catch. lol. If I didn't *know* how much shorter the Tri the Creek course was than the Rattlesnake course, I'd have been really disappointed with my run being three minutes slower this weekend than a month ago. Instead, I'm psyched that I ran three miles at sub-10 minute pace. 90% of success is half mental. |
| 2009-08-17 3:46 PM in reply to: #2353996 |
| over a barrier | Subject: RE: Course distance measurements I take GPS with a grain of salt. I start my runs on the same stretch and my first mile changes by almost 20-30 yds. Rarely in the same spot. |
| 2009-08-17 3:51 PM in reply to: #2353996 |
Veteran 294 Papillion, NE | Subject: RE: Course distance measurements I agree that the bottom line is we are racing against each other, no matter what the distance is. But the problem with the races being off a substantial amount is that us newer "sprinters", or anyone for that matter, don't know if we are truly making progress or going backwards. You are figuring a pace off of a certain distance only to find out it was wrong. I am with the OP, I don't care what the distances are, just list them accurately. |
| 2009-08-17 3:51 PM in reply to: #2354037 |
| Alpharetta, Georgia | Subject: RE: Course distance measurements jezzieswims - 2009-08-17 3:38 PM the bear - 2009-08-17 1:31 PM There is no certification of tri course distances as there is for road race distances, so you're going to find discrepancies in nearly every case. If the run bothers you, you don't even want to begin to think about swim courses. Bottom line is that everyone runs the same course, so competitively it doesn't matter. ^^^ I agree, we all run the same course. I've run races where the run courses were short by .5 miles or over by more than a mile or a 500y swim course turning out to be more like 700y+. Yeah, they throw off pacing but we're all in the same boat. I also agree that everyone is in the same boat/course for that day. My issue comes when the race course is (knowingly) grossly short or long, and people are vying for their OWN PR at that given distance. It's a little disheartning to realize you really didn't PR that half marathon after hearing the RD admit (days later) that the course was .3 short due to a flooded area. (true story) At least tell participants the day-of if you know the course distance has changed - that's what I'd like to see. Edited by lisac957 2009-08-17 3:52 PM |
| 2009-08-17 3:57 PM in reply to: #2353996 |
Champion 8766 Evergreen, Colorado | Subject: RE: Course distance measurements I'd also like to point out that you have no way of knowing exactly where they started/ended their measurements versus where the timing company might have put the mats. I always just use the race distances no matter what my personal bike computer or GPS might say. How do you know they were not starting the distance tracker at the exit to transition but you started yours at the mount line? Also, as others have stated...GPS isn't the be all/end all. It can be off. 3.01 verus 3.1 versus 3.2? Come on...get over yourself...call them all a 5k because you really don't know if your GPS was right or not. Now, the one where a volunteer was in the wrong spot...yes...fine...accept that the race distance was wrong. It happens. Everyone ran the same course, report your accurate pace if you really want to...who cares what the results say? |
| 2009-08-17 4:03 PM in reply to: #2354094 |
Sensei Sin City | Subject: RE: Course distance measurements Normally, they are close enough to not matter to me. However, there is one particular race that I do that is GROSSLY in error. It got a little frustrating when they said the bike was 12 miles and I was on mile 15 or so and nowhere close to T2.. It may have not made a difference physically, but it didn't help mentally. It may sort of get someone a little off their game. Trick is to not let it affect you. |
| 2009-08-17 5:53 PM in reply to: #2354094 |
| Regular 100 Denver | Subject: RE: Course distance measurements jldicarlo - 2009-08-17 2:57 PM I'd also like to point out that you have no way of knowing exactly where they started/ended their measurements versus where the timing company might have put the mats. I always just use the race distances no matter what my personal bike computer or GPS might say. How do you know they were not starting the distance tracker at the exit to transition but you started yours at the mount line? Also, as others have stated...GPS isn't the be all/end all. It can be off. 3.01 verus 3.1 versus 3.2? Come on...get over yourself...call them all a 5k because you really don't know if your GPS was right or not. Now, the one where a volunteer was in the wrong spot...yes...fine...accept that the race distance was wrong. It happens. Everyone ran the same course, report your accurate pace if you really want to...who cares what the results say? lol. It's been a while since I've been told to get over myself on the internet... So I guess your answer to my original question is no, you're not bothered by inaccurate course measurements. As I said, I don't really care what the actual distance is, just that I *know* what the actual distance is. I mean, they give you your times down to the 100th of a second, yet the distances can be whatever. Heck, why do they bother with split times at all and not just give everyone their total if people don't care about their times and paces? All I really want to know is what my actual pace is and now that you guys are telling me I can't count on the GPS, I guess I need to start doing more pure running races where they actually measure the course if I want to know that. |
| 2009-08-17 6:10 PM in reply to: #2353996 |
Expert 1118 , North Carolina | Subject: RE: Course distance measurements I time myself EVERY single time I run. I think I know my pace well enough by now to know what I'm capable of running even without a garmin. I feel CERTAIN that my first Triathlon run course was shorted. I was running up a hill about as fast as long-legged guy was walking. In other words.... sloooooow motion. There is simply no way I ran that race in the time they chipped me. |
| 2009-08-17 6:25 PM in reply to: #2354314 |
| Alpharetta, Georgia | Subject: RE: Course distance measurements BobJ123 - 2009-08-17 5:53 PM jldicarlo - 2009-08-17 2:57 PM I'd also like to point out that you have no way of knowing exactly where they started/ended their measurements versus where the timing company might have put the mats. I always just use the race distances no matter what my personal bike computer or GPS might say. How do you know they were not starting the distance tracker at the exit to transition but you started yours at the mount line? Also, as others have stated...GPS isn't the be all/end all. It can be off. 3.01 verus 3.1 versus 3.2? Come on...get over yourself...call them all a 5k because you really don't know if your GPS was right or not. Now, the one where a volunteer was in the wrong spot...yes...fine...accept that the race distance was wrong. It happens. Everyone ran the same course, report your accurate pace if you really want to...who cares what the results say? lol. It's been a while since I've been told to get over myself on the internet... So I guess your answer to my original question is no, you're not bothered by inaccurate course measurements. As I said, I don't really care what the actual distance is, just that I *know* what the actual distance is. I mean, they give you your times down to the 100th of a second, yet the distances can be whatever. Heck, why do they bother with split times at all and not just give everyone their total if people don't care about their times and paces? All I really want to know is what my actual pace is and now that you guys are telling me I can't count on the GPS, I guess I need to start doing more pure running races where they actually measure the course if I want to know that. I agree with Bob here. There is a reason we measure times and distances. Someone else can disagree all they want, but to tell them to "get over themselves" is pretty rude, IMO. Just because it's not important to YOU, doesn't mean everyone else should automatically dismiss it. Edited by lisac957 2009-08-17 6:26 PM |
| 2009-08-17 7:04 PM in reply to: #2353996 |
Expert 2555 Colorado Springs, Colorado | Subject: RE: Course distance measurements Accurate distances aside, sometimes you can't even count on the distances being the same year to year at the same race. Trying to compare different races is almost useless as well. It's rare that all distances are the same and accurate in different races. Bike course profiles can impact running as well. |
| 2009-08-17 9:23 PM in reply to: #2353996 |
Expert 1053 Culpeper, VA | Subject: RE: Course distance measurements In every event I've done so far, the bike course mileage does not match up to what the stated mileage is on my bike computer. My first one was a few miles longer and the second was a mile and half roughly. My OWS was listed as 750m, but was more like 820m supposedly and even longer due to poor sighting. Run course was supposedly a bit short for the same race, but my worst 5K time to date... so I'd rather it be longer.  So for that one race the swim was longer than billed, so was the bike course and the run was supposedly a tad short. Seems that courses do not tend to be accurate to what they are billed as. |
| 2009-08-18 12:37 AM in reply to: #2353996 |
Master 1651 Breckenridge, CO | Subject: RE: Course distance measurements BobJ123 - 2009-08-17 2:26 PM In your experience, are courses generally accurately measured? Almost never. I usually map the courses after the races with the Route Manager on this site so I know my real speeds. If the course is a loop it's easy to determine exactly what the distance was since you can zoom in close with the sat photo and start/end exactly on the timing mats. On out-and-backs it's much harder unless the turn-around is at a very obvious place like the Tri-the-creek bike route (which is way short of what they claim). I think the exception to the rule is the 5430 long course. On both the bike and run they've put in little out-and-back spurs to get the distances correct. |
| 2009-08-18 12:47 AM in reply to: #2354411 |
Master 1651 Breckenridge, CO | Subject: RE: Course distance measurements Donskiman - 2009-08-17 6:04 PM Accurate distances aside, sometimes you can't even count on the distances being the same year to year at the same race. I think that's probably the main issue. The RDs probably do not know for sure what the courses will be with 100% certainty at the time marketing materials are created. Plus, it's not reasonable to require RDs to create new artwork and such every year as the courses changle slightly due to permitting or construction or whatever. But IMO once the actual courses are determined, USAT should require RDs to post accurate distances in the results and in the split paces. With today's mapping software, it would only take them a couple hours at most to determine exact distances for the results. |
| 2009-08-18 9:03 AM in reply to: #2353996 |
Pro 5011 Twin Cities | Subject: RE: Course distance measurements Generally, the runs are pretty accurate--maybe a tenth here and there, but on the whole (unless there is a last minute course change or whatnot), they tend to be okay. Bikes may vary a bit more--esp. in a new race or when the course changes. But TYPICALLY they are within what I consider a fair margin of error (meaning, it could be my computer...or it could be my riding or it could be measured wrong). The swim, well... while a few races hit it spot on (and then sink the bouy markers, so they STAY right on every year)...I've done very well-established, long running, well-respected races that can't get the swim right to save their lives. One race I've done for years has an "800 meter" swim. It's been anywhere from (roughly) 400 meters to 1200 meters. And of course, in all of those, you have to count in where the mats are and what gets included in T1 and 2 and what gets counted into the leg measurements. A run course may be measured out at 3.1...but when the mats get put down, it may end up at 3 even or 3.2 or... In the end, tris are just a different beast than, say, a running race or a master's swim meet. I don't compare my 5k tri time across races, b/c the factors are too varied. If the course is the same, I may look at my times from year to year (but even that doesn't always work...see the swim example above)...but in general, I look at how I did in relation to "known competitors", how I did in relation to the field, and, most importantly, how I felt. So yeah, sometimes distances can be a bit off. Definitely in the swim, occassionally on the bike, and every once in a while on the run. But I guess I don't think much about it, other than to note it as an aside in my logs. If I see my swim split for an "800" was 16 minutes, I'm like "Oh poo...the swim was probably long." (assuming I look at other folks, and they are similarly long, and not that I didn't like swim off course or something) And then I'm like "DAMNIT. I HATE when I have to swim more than I need to :p" And then I move on, b/c if it was long for me, it was long for everyone. |
| 2009-08-18 9:29 AM in reply to: #2355256 |
| Member 51 | Subject: RE: Course distance measurements Someone might have mentioned this, if so I didn't see it, but there's also the issue of the tangents. Courses are measured apex-to-apex. If you run wide, you're over-taking people, you're always staying to the left etc, then the distance will be different. I ran a NYRR half-marathon at the weekend. Ryan Hall & Paula Radcliffe in attendance, so you can be sure they measured it correct. Came out as 13.3 on my Garmin. I'd put most of that down to me not hitting the apexes on a course with a lot of turns. |
| 2009-08-18 9:54 AM in reply to: #2353996 |
Member 55 | Subject: RE: Course distance measurements I also ran a sprint last weekend and although I had no GPS, the run splits (including my own) indicated that the course probably was off by as much as half a mile. It was a trail run, so I would imagine the trees+ gps = inaccurate measurements. It was pretty annoying to see a 5k time 7-8 minutes slower than my normal run split. |
| 2009-08-18 10:10 AM in reply to: #2355351 |
Champion 8540 the colony texas | Subject: RE: Course distance measurements vitalstatistix - 2009-08-18 9:29 AM Someone might have mentioned this, if so I didn't see it, but there's also the issue of the tangents. Courses are measured apex-to-apex. If you run wide, you're over-taking people, you're always staying to the left etc, then the distance will be different. I ran a NYRR half-marathon at the weekend. Ryan Hall & Paula Radcliffe in attendance, so you can be sure they measured it correct. Came out as 13.3 on my Garmin. I'd put most of that down to me not hitting the apexes on a course with a lot of turns. i think this ^^^ accounts for more than people realize.. I've been on group rides where multiple people have garmins, and we all end up with different distances since we are not on the same tangent around corners and such. If you are doing the same race and they keep the same course you at least can know your PR for that course (even distance) but like Lisa mentioned if you are traveling to different races you really can have a hard time comparing your time by distance. |
| 2009-08-18 11:58 AM in reply to: #2355468 |
Master 1651 Breckenridge, CO | Subject: RE: Course distance measurements Gaarryy - 2009-08-18 9:10 AM vitalstatistix - 2009-08-18 9:29 AM Someone might have mentioned this, if so I didn't see it, but there's also the issue of the tangents. Courses are measured apex-to-apex. If you run wide, you're over-taking people, you're always staying to the left etc, then the distance will be different. I ran a NYRR half-marathon at the weekend. Ryan Hall & Paula Radcliffe in attendance, so you can be sure they measured it correct. Came out as 13.3 on my Garmin. I'd put most of that down to me not hitting the apexes on a course with a lot of turns. i think this ^^^ accounts for more than people realize.. I've been on group rides where multiple people have garmins, and we all end up with different distances since we are not on the same tangent around corners and such. Garmin's location readings are not accurate enough to account for tangents on a road race course. If you ran a perfectly straight line for exactly 3 miles, any GPS device (except maybe those used in military/aviation) is going to produce a route map that is zig-zagged to differing degrees due to errors in the location readings. That's why a bunch of Garmins on virtually the same course will come up with different distances. Edited by breckview 2009-08-18 11:59 AM |
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