This is my first post. I just started Level 1 Marathon training plan from TP.
I did a LTHR test last week.
15 min warm up + surges at pace.
20 min test, average HR in last 15 min of test.
I went all out on the test and came up with a LTHR of 177.
I went to do my first run today and it was a Fast Finish Run.
The last 5 min were to be at CV (which for me = 181-186)
According to the write up, CV is supposed to be the max pace I can sustain for 30 min.
But my confusion is the LTHR test was the fastest I could sustain for 20 min. How is CV zone higher than LTHR? I was not even able to get into that zone for the last 5 min.
LTHR is actually the fastest pace you can maintain for 60 minutes. This is an unreasonable test for athletes to perform every rest week, so we simulate and estimate that 60 minutes with the the more palatable 20-minute test.
And, the test is not based on the full 20 minutes, it is based on the final 15 of the 20-minute test. There is just going to be some squishy numbers, particularly for HR, when not performing a full 60-minute test.
Additionally, when using HR for anything higher than Zone 3, it’s going to take several minutes for your HR to “catch up” and it is common to not hit HR targets for Zone 3+. Using Pace or Power for those high intensity intervals is better. In fact, Pace and Power will be better for you across the board, as we find the 20-minute LTHR tests more closely align with Pace and Power over HR.
Regardless, you should be able to run faster for 5 minutes than 20, so the result of the workout should be the same regardless of what BPM you hit: CV is faster than LTHR, so run those 5 minutes faster than what you ran for your 20 minute test.