[Scott Johnston]

Antonio:

Thanks for your kind words and also for writing in with your question. when the paste to heart rate ratio is negative it indicates that the second half of this run’s pace increased relative to heart rate.  just eyeballing the graph I can see that that happened. I can’t explain why it you sped up. But, just scanning your heart rate pace, chart from the workout I can see that you definitely sped up and heart rate remained quite constant. My best guess is that you need to try starting at a higher heart rate.  since you are training for a mountaineering event, it might make sense to do this on an inclined treadmill hiking if that is the way you’re going to be doing a lot.  However, if you plan to do most of your training, running on the flats, then this is probably the way you should determine your aerobic threshold.

I hope this helps,

Scott