So I'm trying to figure out if they're right or not because I'm 42 and I've been a night owl since 12 and yeah, nowadays my health is quite bad and I'm busting my arse trying to fix it.
Your circadian rhythm regulates melatonin release. Not the clock hanging on your wall.
From your other comment, seems like your problem is a very inconsistent sleep pattern and not enough sleep.
Sometimes I sleep 4-5h and then have a huge nap -- 2.5h to 3.5h -- in the early evening. Happens for a week or two. Then I go without naps for a month.
It's relatively cyclical but the periods aren't with fixed values at all. The daily hours are fairly inconsistent as well.
Guess I'll keep going to doctors like I do lately.
But I did hear from a few trainers and doctors that melatonin can be taken without prescription and is not dangerous, hence my question above.
I'll ask my doctor next time about it.
So I must complete heavy workouts every 1-2 days to make my body want to sleep. Maybe start heavy exercise when you feel you're getting near that point.
For me - it is a weight workout (lifting or power lifting). I can do a 1-2 hour cardio workout (or sprints) to get a similar effect.