Counterpoint: I started having the worst insomnia ever after I started lifting. I feel like my adrenaline level is higher now. I love lifting, and it has a lot of benefits, but for me, better sleep is not one of them. I also noticed it made my restless leg syndrome worse. Stretching and getting back on magnesium seems to have helped that, but my sleep quality and duration is still shit.
Tip: since you're on magnesium, try magnesium glycinate if that's not already the kind you take. Glycine helps you sleep, especially if taken at night.