Chain of Rocks Bridge

Summary Data
Total Time (h:m:s)	1:52:27	9:21 pace
Moving Time (h:m:s)	1:51:26	9:16 pace
Distance (mi )	12.01
Moving Speed (mph)	6.5 avg.	8.9 max.
Elevation Gain (ft)	+1,656 / -1,667
Avg. Heart Rate	146 bpm	Zone 3.9
Temperature (°F)	53.8°F avg.	55.4°F high
Wind Speed ( mph)	SSE 11.2 avg.	SSE 12.6 max.

Start Time: 08:58:35 AM CST

Perfect day for a long run---not too sunny (but some sun) and low 50s the whole run. Missouri and Illinois have converted the old Chain of Rocks bridge across the Mississippi to a bike/run trail---making it the longest bike/run bridge in the US (possibly world). Hard to believe that this two-lane bridge ever served much traffic, but thinking back to the 60s, the limited road travel would have made it crowded, but not unreasonable. Throughout the run I had that 'I can run forever' feeling and had to work to keep myself around a 9:10 pace (rather than the 8:00 that kept sneaking out). The pace was excellent---and felt healthy (e.g., not damaging myself) if slow. Killer hill at the beginning and end---the end one, during the 11th mile, was the only time I thought, 'hey, I'm ready to be done'---but even then I was able to keep a pretty decent pace.

Found myself hungry at the beginning---this is always a problem with starting a run/ride later in the morning---if I just woke up and ate, I would be fine, but I do not and I end up wishing that I had eaten something more. Reading something online a few days ago, it was suggested that one eat .7 x bodyweight in grams of simple carbs within an hour of completing a long run. That translated into a banana, two 8oz milks and five waffles (3 with apple butter, 2 with grape jam). Seemed bizarre, but it really worked for me and I feel great just a couple hours later.

As I was running, it occurred to me that Motionbased would have a particular bug---namely that rather than taking actual altitude data, it takes geological survey data and retroactively applies it to the workout (adjusting distances, etc.). Since I was running over two bridges that were significantly higher than the water height, I figured that the survey data may have used the road data (the Chain of Rocks bridge was a part of Route 66 and so it has been around long enough to appear in virtually any dataset)---but the more likely assumption would be that Motionbased uses geographical data, not road data. Drumroll? Indeed it uses geo data with the result that Motionbased skews distance and elevation data dramatically for this run---it shows one going down to the river and then back up rather than up to the crest of the bridge and back down again. With two bridges, this is even more skewed.



Updated 12/26: Thanks to a comment from trailblazer, I have updated the chart above to reflect 'uncorrected' data from the run. This doubles the amount of climbing and shows a much different elevation profile than the run above.