BeDe, The seconds/mile is just a comparison between runs of a similar nature. The way I get 3secs/mile for each beat is by taking 2 runs and comparing them.

Example:

Run 1. 10miles@120 = 8:30pace

Run 2. 10miles@130 = 8:00pace

The difference is 10bpm for 30secs/mile, therefore for this runner, each beat is worth 3s/mile.

The comparison should be on runs of similar distance, terrain and gradient.

Your indicator is a direct measure of fitness - Pace(in secs)/HR. You have a mix of variables there though, the top number in the divide is pace, so the faster the pace the the lower the seconds the lower the result. The bottom number is HR and the lower this number the higher the result?

Your indicator would be better as speed(mph)/HR. The higher the speed, and the lower the HR, the higher the result.

Beats per mile works the other way. The lower the result the better. Pace*HR - The lower BOTH these variables the lower the result.

Sorry for my waffle.

Edited: 22/02/2013 at 09:01