Today's run wasn't the greatest. I didn't take advantage very well on the down hill sections, and I just wasn't in the game mentally. My heart rate got clear down into the lower 130s. In fact, 10 of 24 laps were in the 130s. I was 4 minutes slower on this course than last time, or 0.3 mph, or 8 beats per minute. I'm starting to wonder not only how fast I would go at 165 bpm, but even if I have the will power to exercise that strenuously anymore.