Course 5km when saved is only 4.85km long?

can you post a link to the activity?

Hi JSPICKERNELL,

I attached two different runs, both 5 km.
http://connect.garmin.com/modern/activity/495029032
http://connect.garmin.com/modern/activity/502889758

Nobody? Any ideas??

When you convert to a course, a lot of the data points in the original activity data are lost. This makes the course file smaller, but has the side effect that it the accuracy of the route is reduced. The amount of error depends on the complexity of the course (the number of turns and their size) as well as how close the resulting line is to the original. If you record a 3.1mi run on a path that is relatively straight, the resulting course will be very accurate. If you record 3.1mi on a path that has lots of turns, it is likely that it will be inaccurate.

This is pretty obvious if you have a look at this activity and the course created from it. If you compare the maps, you'll see that the long straight stretches are accurate, but the position data from the neighborhoods are very different.

Travis

Thanks for your response Travis, as usual you know how to explain it. But I dont get how in your example, the distance still stays exactly the same ?

In that case, the estimated path is very close to the actual path in distance. As you can see, 95% of that activity is running on long straight lines, and the areas that aren't straight are fairly small, so the error is small.

Travis

So I could save my run as a course, and then alter the path so it will be 5 km instead of 4.85km? The hills have nothing to do with it? Very up and downy it is, very steep hills. Eventually I thought that could cause the problem.

So I could save my run as a course, and then alter the path so it will be 5 km instead of 4.85km? The hills have nothing to do with it? Very up and downy it is, very steep hills. Eventually I thought that could cause the problem.

Ok, I altered it manually! Exactly 5km now. ;) Thanks again!

Thanks Travis - I hadn't realised until looking at this example that when you save a run as a course it uses less data point - that's rather irritating and seem sto undermine the usefulness of the save course feature - seems pointless (pardon the pun) to save data on courses when the majority of data on the connect site used by activites