When you take measurements, do you flex or are the muscles relaxed?
You take flexed and unflexed measurements, but most of the time measurements are flexed.
f0ck, I don't even wanna measure my arms unflexed. ever.
Measurement is way to track progress. As long as the measurements are reliable, it doesn't matter how you do it.
If you are that picky, you can do flexed and relaxed.