Discussion: hill

No guesses on the HR glitches, but I'm wondering what might be causing the hill issue. It consistently happens when you're running past something on the sidelines that looks like a small set of bleachers? Anything in that vicinity that might be causing RF interference? You're also between the two light poles, although the two poles on the opposite side of the track aren't causing any problem.

There are bleachers/hill all along the east side of the track, but not more than 3-4 meters high.

Just look at the USGS map. The track is far from flat.

How 'bout that! I also don't know if I've ever before noticed a contour labeled with a "3" before. A bit surprising that Fresh Pond is at only 2 meters MSL.

CSU O map at 2m has track on a plateau and flat as a pancake! cambridge remodelling :-)
re HRM, known sources of spurious recording include 1. poor conductivity skin/sensor (not enough sweat or no electrode gel) 2. static (usually clothing), and 3. electromagnetic interference (eg powerlines).
Interestingly the spikes appear to occur at the locations of the stadium lighting poles- (was it on perhaps?) and are somewhat synchronous with the elevation blips- so could be same source for both perturbations.

I think PG has identified the hill. It comes not from Ian's GPS from from the SRTM data (Jan 2000) that AP uses for elevation correction. I think the track was built in 2003.

Also on HRM, I just replaced my battery, my HR seems way less erratic... might help?

Does AP use elevation data from the GPS at all, or does it just take elevation from the model? (GPS elevation is, in my experience, pretty bogus for running applications.)

Elevation data from the watch is only used if you have correction disabled in your settings, if you export direct from sporttracks without using the elevation plugin, or if there is some error during correction.