I took my new Forerunner 305 out for its first run in overcast conditions today. It worked flawlessly. Even with cloud cover and tree-lined paths, it never lost the signal. The heart rate monitor works great as well.
Today was my first day of speedwork since starting Heart Rate training. Ran 6 miles total. Today's workout was 1.8 miles warmup @65%HRR (the odd distance was to get me down to the paths alongside the Isar river, which are relatively flat, straight, and don't involve crossing any major intersections), then 1 mile of striders (which consist of accelerating for 100m, followed by an easy jog for 100m), then the speedwork: 4 x 200m @80%HRR with 200m recovery between each one, finishing up with a cooldown of 2 easy miles @65%HRR.
So what's this HRR? Heart Rate Reserve (HRR) describes the difference between a person's Resting Heart Rate, and Maximum Heart Rate. This is what I use to determine my proper training zones. As a person becomes more fit, as their HRrest will drop, the Heart Rate Reserve will increase.
- HRR = HRmax − HRrest
THR (Target Heart Rate) = (HRmax − HRrest) x Intensity + HRrest
So, for example, for my 80%HRR intervals, I determine my THR this way. My HRmax is 213 bpm, my HRrest is 55 bpm, and the desired intensity is 80% (or 0.8).
THR = (213 - 55)x0.80 + 55 = 181.4
If you are interested in learning more about Heart Rate Training, an excellent site is the Sports Coach site.