Taking course elevation into account when trying to run even splits

TheRoadRunner

Not too sure if I posted this before so apologies if I have.

A couple of years back I ran the Boston marathon and in the expo Nike were handing out wrist bands for target times. The splits were unique though. Instead of assuming the course was even, different miles had different projected splits based on the course elevation. You told the techinicians your desired finish time and they created a wrist band for you.

For example if you wanted to run 3hours your average split would be 6.54 (or thereabouts) on a flat course. However the band in Boston averaged your splits and accounted for fast and slow miles. It is a bit of a gimmick but was a great idea. The first 5 miles in Boston are slightly downhill so the band told me to expect 20 seconds per mile quicker than the average pace. Miles 17-20 are slightly uphill so mile splits 30 seconds slower than the average were expected here. I didn't pay too much attention to the band until late in the race when my splits were slowing but it was reassuring to know that the last 2 miles were projected to be faster and so it proved.

Long story short does anybody know of an online tool that might be able to do something similar with GPS data ?

robinph

Interesting idea.

This site seems to have pace band calculators based on the elevation profiles, looks like you have to pay for them though:

http://www.mymarathonpace.com/Home_Page.html

Gringo78

TheRoadRunner wrote: »

Long story short does anybody know of an online tool that might be able to do something similar with GPS data ?

Interesting, never thought of doing something like that even though that is the way I intend to run the marathon, ease back on the uphills.

Mapmyrun.com does a .csv file export of the elevation of a route....if you had a link to the course on mapmyrun.com I could modify an excel tool I already have to do that for you easy enough in excel...had been messing about with it for Connemara. Will try something tomorrow and post it up for Connemara.

robinph

The tricky bit is by how much do you alter the pace and for how much of an elevation change over a mile do you consider as relavent?

Aimman

robinph wrote: »

The tricky bit is by how much do you alter the pace and for how much of an elevation change over a mile do you consider as relavent?

Sounds like an opportunity to apply for a sports research grant and spend the majority of it in the pub discussing the results at the end :-)

Its a good idea and puts more of a realistic outlook on the contour of the route. I'd like to see anyone stick to a linear pace for the Full Donegal Mooathon.

TheRoadRunner

Gringo78 wrote: »

Mapmyrun.com does a .csv file export of the elevation of a route....if you had a link to the course on mapmyrun.com I could modify an excel tool I already have to do that for you easy enough in excel...had been messing about with it for Connemara. Will try something tomorrow and post it up for Connemara.

Will do. As a positive control I could find the elevation of Boston and you could import the data into your excel macro thingy. We could then compare your projected splits with the Nike ones. I still have the wrist band and even though I didn't actively try to hit the splits I wasn't too far away from them.

I won't disclose the Nike splits until you report back.

Super nerdy or what

robinph

The splits that they gave for Boston would give an idea of a sensible scale to work from in the adjusting of pace to the profile. Sounds like just taking the Mapmyrun elevation data would be the simplest, I guess that is just ripping the Google maps terrain data. Otherwise we'll have to get to work on a parser for the gpx file to do it from.

TheRoadRunner

robinph wrote: »

The splits that they gave for Boston would give an idea of a sensible scale to work from in the adjusting of pace to the profile. Sounds like just taking the Mapmyrun elevation data would be the simplest, I guess that is just ripping the Google maps terrain data. Otherwise we'll have to get to work on a parser for the gpx file to do it from.

How is the elevation data from Garmin watches estimated ? is it ripped from Google terrain maps. Now I think of it it probably is. I'm off to find a map for Boston anyway. Will send it onto Gringo

robinph

TheRoadRunner wrote: »

How is the elevation data from Garmin watches estimated ? is it ripped from Google terrain maps. Now I think of it it probably is. I'm off to find a map for Boston anyway. Will send it onto Gringo

The elevation data recorded by the watch, like a 405 etc, is just it's vague guesstimate calculated from the GPS data directly so is not very accurate ad depends on how many satellites it happens to be fixed on at each point along the track. I also have a GPSMAP60CSx which is more accurate to changes in the elevation as it has a barometer built in as well so although it gets the elevation data from GPS satellites, the changes it picks up as you go up and down are more accurate, you can calibrate it though to know elevation points, but as you'd have to do that each time you turn it on it's not worth the bother really.

You can however take the GPS track and then merge it with NASA radar topography data, which sites like http://www.gpsvisualizer.com/ allow you to do, and that will improve the elevation data that the likes of the 405 will have collected.

Actually just noticed that site, as well as producing lots of pretty lines on Google maps for you, will also convert the GPX tracklog to a csv and add in the elevation data. So if you have the track of a race, and can't be bothered to map it out in Mapmyrun then you could use that to convert to csv and then put it into Gringo78's Excel to hopefully spit out whatever he manages to get it to spit out.

TheRoadRunner

robinph wrote: »

The elevation data recorded by the watch, like a 405 etc, is just it's vague guesstimate calculated from the GPS data directly so is not very accurate ad depends on how many satellites it happens to be fixed on at each point along the track. I also have a GPSMAP60CSx which is more accurate to changes in the elevation as it has a barometer built in as well so although it gets the elevation data from GPS satellites, the changes it picks up as you go up and down are more accurate, you can calibrate it though to know elevation points, but as you'd have to do that each time you turn it on it's not worth the bother really.

You can however take the GPS track and then merge it with NASA radar topography data, which sites like http://www.gpsvisualizer.com/ allow you to do, and that will improve the elevation data that the likes of the 405 will have collected.

Actually just noticed that site, as well as producing lots of pretty lines on Google maps for you, will also convert the GPX tracklog to a csv and add in the elevation data. So if you have the track of a race, and can't be bothered to map it out in Mapmyrun then you could use that to convert to csv and then put it into Gringo78's Excel to hopefully spit out whatever he manages to get it to spit out.

Jaysus I have a headache. I've attached an elevation csv file for the Boston marathon.
The splits I have are for a 2.50 marathon.

robinph

How do the Boston times compare with other courses, they surely can't compare times for the record books with it being so downhill?

TheRoadRunner

robinph wrote: »

How do the Boston times compare with other courses, they surely can't compare times for the record books with it being so downhill?

You are right in general the course is slightly downhill and because of that the IAAF won't recognise world records/bests that are set on it.

Krusty_Clown

Just bear in mind that mapmyrun data may not be granular enough to follow the elevation profile of the road, but instead, follow the elevation profile of the surrounding landscape. You might think that these are generally the same, but road builders will generally find the most economical route between two points, which often means removing hills (take a look at the N4 near the toll-bridge!). Mapmyrun also seems to do a lot of elevation smoothing.

Probably the best thing to do is to use a GPS tracklog in sportstracks, using their elevation correction plugin. Then do your elevation-based pace band. It's a solid idea in principal, but doesn't take into account an individual's strengths. Take Slogger_Jogger for example. Born on a hill and generally eats hills for breakfast. He's going to be less impacted by the hills than Joe Bloggs who lives and trains on flat tarmac roads and grassy pitches.

gmaclin

robinph wrote: »

Interesting idea.

This site seems to have pace band calculators based on the elevation profiles, looks like you have to pay for them though:

http://www.mymarathonpace.com/Home_Page.html

Hi all:

I happened to run across this forum/thread and wanted to let you know that I'm the owner of the above web site and the author of the terrain-adjusted pacing spreadsheets available from that web site.

I have been working on the solution to the exact problem described here for the last 3+ years and believe me, it's not as simple as you may think. My pacing spreadsheets allow you to take a lot of different factors and pacing strategies into account with just a few clicks of the mouse, while also taking into account elevation measurements taken every 0.05 miles.

If you want to see my latest version of the spreadsheet, download the free trial version I did for Boston and try it out. The only limitation on the free version is that you cannot print the pace bands (you will get an error).

Good luck to everyone running Boston this year!

Greg

Gringo78

gmaclin wrote: »

I have been working on the solution to the exact problem described here for the last 3+ years and believe me, it's not as simple as you may think.

I believe you.....I was working on this a few nights ago and didn't sleep a wink. Got the basic one working but trying to incorporate in selectable ability running downhill and uphill is giving me a little bit of trouble when inputting very hilly or very downhill marathons. Almost there I think though, can maybe post the one for Boston tomorrow but it wouldn't neccessarily work so optimally for other marathons, although I think I am close now.

gmaclin

Gringo78 wrote: »

I believe you.....I was working on this a few nights ago and didn't sleep a wink. Got the basic one working but trying to incorporate in selectable ability running downhill and uphill is giving me a little bit of trouble when inputting very hilly or very downhill marathons. Almost there I think though, can maybe post the one for Boston tomorrow but it wouldn't neccessarily work so optimally for other marathons, although I think I am close now.

I came up with a basic solution 3 years ago and have been fine tuning it ever since. If you want to see an example of my latest version, download the trial version of my "Boston Marathon Pacing & Info" spreadsheet from here (it's free):

http://mymarathonpace.com/Pacing_Spreadsheets.html

Greg

gmaclin

robinph wrote: »

How do the Boston times compare with other courses, they surely can't compare times for the record books with it being so downhill?

I have put quite a bit of research into the answer to this question. Take a look here and scroll to the bottom of the page (you will see my "Marathon Course Time Predictor" at the bottom of the screen):

http://mymarathonpace.com/Elevation_Charts.html

I also have a lot of information I've collected on "The effect of hills on running and pacing" here:

http://mymarathonpace.com/Other_Info.html

If you look through my web site I think you'll find a lot of other good info as well.

Greg

Sklarker

gmaclin wrote: »

I have put quite a bit of research into the answer to this question. Take a look here and scroll to the bottom of the page (you will see my "Marathon Course Time Predictor" at the bottom of the screen):

http://mymarathonpace.com/Elevation_Charts.html

I also have a lot of information I've collected on "The effect of hills on running and pacing" here:

http://mymarathonpace.com/Other_Info.html

If you look through my web site I think you'll find a lot of other good info as well.

Greg

I've calcluated changes to average pace for each km of the Great Ireland Run using Greg's excellant link and elevation data from mapmyrun:
0.15%
0.17%
-0.44%
-2.22%
-1.64%
0.86%
1.57%
3.73%
3.45%
0.37%
kinda correlates ok with my splits from '08 but I got caught up in the masses at the start that year

Gringo78

Excel file was 2mb so too large to attach but if you PM me I can email it or else explain how it can be uploaded to google docs? Does a macro run in a google docs excel file?

gmaclin

Gringo78 wrote: »

Excel file was 2mb so too large to attach but if you PM me I can email it or else explain how it can be uploaded to google docs? Does a macro run in a google docs excel file?

Attach it to an e-mail and send it to me at: gregmaclin@gmail.com

Greg