Any workout for testing LTHR?

Hello people!

Without any medical tests, I’ve got some problems to correctly identify an approximate value for my LTHR. According to Joe Friel, a potential test would be:

To find your LTHR do a 30-minute time trial all by yourself (no training partners and not in a race). Again, it should be done as if it was a race for the entire 30 minutes . But at 10 minutes into the test, click the lap button on your heart rate monitor. When done, look to see what your average heart rate was for the last 20 minutes. That number is an approximation of your LTHR.

My question is the following: can you incorporate this protocol with an existing TR workout? If so, which one would you recommend?

Lola seems to be a good choice but I’d enjoy to read what would be your own decision!

30 min free ride would probably be best.