Average Beats per Mile

Since starting aerobic training some months back, I've analysed a lot of data and come up with a metric of "Beats per Mile" to indicated some level of aerobic fitness. It's a bit experimental, but I think it's interesting enough to track. It works like this - if you run an 8 minute mile and your average heart rate is 165bpm, you will be running at 1320 beats per mile (8 x 165 = 1320). If you can achieve the same speed (8 minutes per mile) with a heart rate of only 140bpm, your beats per mile will be 1120. The value displayed in the data field is the average of your complete activity. Lower values are better. Your starting point will be specific to you, but aerobic system improvements should results in a drop in this metric over time. I personally started around 1400 beats per mile on average, and through 5 months of aerobic training I've dropped to around 1100 beats per mile and broken 5K, Half Marathon and Ultramarathon PBs.