More exercise could make for better sleep

I often wonder how people get paid for such obvious conclusions - but here we go:

A new study suggests regular physical activity might encourage better shut-eye: People who met national exercise guidelines reported better sleep and less daytime fatigue than those who didn't.

My personal experience has been fairly inconsistent.  I will get better sleep, but only if I had a truly vigorous workout, and (here is the important part) my stress levels are low.  I generally suffer from insomnia - waking in the wee hours of the morning and thinking about everything under the sun.  It could be something worrying me - work, money, book sales, or something personal.  But again, I could mapping out new book chapters, figuring out my next music purchases, or calculating the best way to travel to an upcoming destination.

The only 'cure' I've found for this night restlessness is the supplement Melatonin.  I take 5mg (dose will vary by individual) every night before I go to bed.  This 'hormone of darkness' has finally allowed me to sleep better than the past ten years.  I'm no doctor, so don't come running to me if you have an adverse side-effect.  So here's a legal disclaimer:  Always consult your physician before taking any supplement.  Having said that - the improved sleep has bettered my mood, reduced anxiety, made my workouts better, and even allowed me to eat less junk food.  Side-effects?  I feel a little groggy in the morning, but nothing as bad as sleeping pills or cold medicine.