The Guided Letting Go Theta meditation lasts just over an hour
, but this will not seem like an hour because you'll find your perception of time changes when you're doing it
. Most people who've done the meditation for the first time think that it's only lasted 20 minutes or half an hour at the most and are amazed when they find out they've been meditating for over an hour, which for many of them is far longer than they've ever meditated for in a single sitting.
The Power Sleep track is just under 40 minutes in length, but you don't have to listen to it until the end - Jono tends to listen to it for only 20 minutes to half an hour while he's doing some reading and reflection before bed. Experiment with it and you'll soon discover what works best for you.