Which workout to best test with regularly?

Is there a ‘best’ workout that can be used regularly to evaluate performance at all intensities, especially to track changes in LT1 and 2?

“Tests” are best performed in situations where you are going to be motivated to push yourself. For best results, you want max efforts to occur at various intensities and the efforts to be held. If you insist on following a protocol, we have 3 test workouts you can use. Folks on FB have suggested doing a hard group ride or Zwift ride to establish your signature.