When that happens to me it's often because I'm ruminating about something, can't get it out of my mind and relax. If that's what's keeping you up, CBT (cognitive behavorial therapy) techniques can help to stop that thought pattern, or just taking some daily action (any concrete action besides just turning it over in your mind) towards resolving the thing you're thinking about can help.
White noise sometimes helps me sleep too, especially after waking up in the middle of the night.
I do powerlifting 3x week. No real aerobics, I should add that but I just hate it. Sometimes I’ll drop the weight and do high rep sets which does get my heart pumping.
My completely unscientific analysis: aerobics gets the blood circulating more and enables the body to remove stress hormones from the blood at a faster rate.
White noise sometimes helps me sleep too, especially after waking up in the middle of the night.