What running on empty looks like

Courtesy of the wrist gps system that my wife uses when we run, here are some interesting graphs of our last two runs.

First, 2 weeks ago, a 7.5 mile run, which was one of our best runs:



A couple of interesting points:
The run started at 9:15 AM, the weather was very cool and slightly damp.
The run as a whole had an average of 6.3MPH
The drop at about 1.6 and 4 were bathroom breaks.
The drop at aout 3.5 was the turn around point.

Now look at this week's run 8.5 mile run:


Some points:
The run started at 3:33, the weather was very warm (especially compared to what I am used to at 9AM).
The drop at 3 was a bathroom break.
The drop at 4 was a turn around point
The drop at 5 was a long re-fill the water bottle break.
The drop at 7 was me completely running out of energy.
I managed to run another half mile between 7.5 and 8, but that was it.

Anyway, it was pretty interesting how different it was to run when it was warm, and also the difference in running late in the day versus first thing in the morning. I made the mistake of not eating a good lunch before my afternoon run, and I ran out of energy. I think the heat made me need a lot more water intake than I'm used to also...