It's better to listen early or later in the day, when you're not feeling sleepy or too tired.
If you listen in bed, be aware that you might just fall asleep and miss out on the programming, so try to sit comfortably, with your head nicely supported, rather than lie down in bed.
Of course, you're in control, and are entirely free to listen in bed if you really want to – just as long as you’re aware that this is the easiest way to fall asleep.
If this does happen, be sure to listen again when you're less tired.