lip trill length

I have trouble keeping the lip trill going for as long as John does in the warmup exercises (from lessons 2 and 3). My lips seem to stop "buzzing". I don't think I'm running out of breath. Any ideas?

Hi, Bell! See here for some tips on the lip trill, and let me know how it's going: https://www.30daysinger.com/blog/lip-trills-all-about-the-vocal-exercise.

Thank you Camille.

By the way, the forum seems to be filled with spam questions in the last day or so. I don't know who to report this to.

We're working on it, Bell! Thank you!