Garmin Connect Information

Thanks for the reply. I am using the 910xt. Also, those are two different courses. I'm just trying to get a feel for how the course I train on will compare to Steelhead.

Edited by jfolks259 2013-07-09 2:22 PM

What happens when you click enable "elevation corrections"?

Just clicked it and all the info stays the same. I don't really think there's an issue with the device, I'm just wondering what elevation number i need to take from Garmin Connect to compare it to Steelhead.

I'm trying to compare the elevation gain of my current training path to what I'll find at Steelhead.

elevation gain is the number you want to look at. the garmin can overestimate in my experience compared to plotting out a course on say mapmyride. From this information your course looks to have more elevation gain than the race course.

What I try and do in the same situation is try to find (or create, if possible) the course I'm comparing to at the same site. I don't know if this is any more accurate in reality, but I feel better if I can look at my recently-ridden course vs. the race I'm planning for, both in Garmin Connect, or both in Mapmyride. You can search Garmin Connect to see if anyone has uploaded the Steelhead course, and then at least you'll be able to see your Garmin uploaded file vs. someone else's Garmin uploaded Steelhead file.

That's a great idea. Thanks for the suggestion!

The 910xt has a barometric altimeter that measures the elevation... I'm not sure what map my ride uses (guessing GPS) but I wouldn't say that map my ride is more accurate,

Judging by your training ride I would say that you are good to go in terms of elevation. If you are concerned you could always find more hills to ride

I would love to find some more hills! It's tough living in Chicago though! :-)

I would trust the 910 over the IM website, which at least for IM Canada were apparently calculated using a mapmyride route.  Numerous actual course rides show consistent elevation of approx 5700, while the "official" WTC map only shows 4600.  The 910 is fairly accurate and uses barometric pressure and does not need elevation correction enabled.

ETA -0 just saw they were two different courses.  I'd trust the 910 over mapmyride as well, which as noted above uses gps coordinates.   At any rate, 732 feet over 56 miles is a fairly flat course

Edited by ChrisM 2013-07-09 6:23 PM

The other thing to bear in mind is the scales of the graphs - the garmin one has a much bigger scale where as the IM one is just a 200feet scale. I think on garmin you can rescale by clicking and dragging the mouse over the area you wnat to highlight. I'd guess you'll see a different looking profile when you rescale the garmin one.

Edited by grahamclarke_6 2013-07-10 2:31 AM

trust what the garmin is telling you. just FYI though, the elevation profiles for the HIM i did earlier this year were off by a factor of 2 from the race website...

Which race was it? Were the #s provided by ironman similar to MapMyRide?

If you use the enable it refers back to a database of known topography based on GPS coordinates, so if your corrected and uncorrected elevations give you the same data, I think you can feel pretty confident in it.

i'm doing this race too and i did a search on Garmin Connect to see if someone had mapped the course already. turns out they have. go to Explore>Courses and search Steelhead with the state set to Michigan. You'll find the run course too. It will give you a pretty good idea of elevation comparisons to your own Garmin Connect activities.

Best of luck!

I'm not sure how elevation gain is defined but I wouldn't be surprised if a Garmin device and a race web site are using different definitions.

Using the example of a climbing a single mountain, for simplicity... If the finish elevation is 1000 ft higher than the starting elevation, one could say that the gain is 1000 ft. (I wouldn't be surprised if race organizers use a similar calculation - they would do this for sum of all of the peaks that the race traverses.)

It's also possible to count every little dip and bump along the way. If one goes up and down a 10 ft bump I assume that Garmin counts this as an elevation gain of 10 feet and an elevation loss of 10 ft. The elevation gain on my 1000 ft mountain will be a lot greater than 1000 ft if all of the smaller bumps along the way are added to the total.

I've made some assumptions - does anyone know how race organizers calculate elevation? Or how Garmin does it? I don't think any one method is correct and even if my assumptions are incorrect, it seems like you need to know the calculation methods before there's much point in worrying too much about comparisons from different sources.
Don

Ok so I've updated the pictures on this thread. I was able to drive out to Benton Harbor today and ride the course. Well I should say part of the course. As soon as I made that major right turn (around mile 11) the roads were terrible! No potholes or anything but just extremely bumpy. So bumpy that the bolts that attach my armrest pad to the base bar actually cracked in half and I had to deal with the armrest just hanging there the rest of the ride (hence why I cut the ride a little short).

But overall I think the information can still be used. The info from Garmin Connect and from Ironman are compared below...

GC:

Max Elev. = 749 ft.
Min Elev. = 273
Elev. Gain = 2,234

Ironman

Max Elev. = 725 ft.
Min Elev. = Doesn't specify but the map shows a point of about 585
Elev. Gain = 732

So the max elevations are very similar but the min and elevation gains are way off. Anyone want to draw any conclusions?