When I do it it's not strenuous. With dumbbells. Arm lifts (to the side and front) and military press using 5lb, bent over rows with 20lb, curls with 5lb, shoulder shrugs with 20, squats with 20. Followed by laying on the floor dumbbell presses with 20lb and pushups. Some sit ups too.
Anything that raises your body temperature is not good before sleep.
Your body temperature has to actually drop a bit lower from normal before all your regular sleep cycles can kick in.
What does before mean in this context? Half hour or 2-3 hours? Unwinding is necessary and half hour is not enough.
This is conjecture--but there might be a difference between aerobic and anaerobic exercise in this case.