I have read some of the past posts about pace vs. heart rate running but have an additional question. I have been training with heart rate. Of note, I have not done a lot of low intensity aerobic training, thus my heart rate spikes very rapidly and Zone 1 and 2 includes a lot of walking. For example, the difference in Zone 2 between Pace and Heart rate is dramatic. To maintain a Z2 per HR it is in the 140s and Pace is around 9:30, but in reality to maintain a Z2 heart rate I am almost 4 minutes slower. Do you recommend to switch the pace, or continue with heart rate until I can build more aerobic capacity? I feel as though “Running” a 13 minute mile is essentially me just walking quickly for a majority of my runs. Thank you!
The first thing I’d recommend is to perform an updated threshold test per our Intensity Guidelines for Running document. Due to the large delta between the two, I suspect your Pace and HR thresholds were tested separately. Unless they are tested at the same time, they are unlikely to align. If tested together, they will align (at least for that particular environment).
For example, if you do the 20-minute TT in our document, you’ll capture both a threshold HR of, say 165 and a threshold Pace of, say 8:10 per mile. So, they immediately aligned and all other zone buckets flow from the same test.
However, even if you test both at the same time, it just improves the chances the two will align. If your training environment (heat, humidity, indoor, outdoor…) significantly changes, your HR will be significantly higher or lower for that same 20-minute TT speed due to environmental conditions.
So, while performing the test will bring the two closer, HR and Pace will still rarely align unless you train in the same perfectly controlled environment all the time.
In summary, I recommend you retest both at the same time, but even then I’d switch to Pace as your primary measure regardless.