Some ideas:

Do you play with them twice per day to release some of that energy?
Use a fishing pole type of toy or laser pointer. Have a play session
right before bed to tire them out.

Do they have a cat tree to climb?

Rotate their toys every few days. Put away some and bring them out
later. They are "new" again (this really works. I do it all the time).
do the same with cardboard boxes, and paper bags (no handles).

Can you put a bird or squirrel feeder near a window. Ours love to
watch the critters.

Some cats like those DVD shows for cats, or "watching" Animal Planet.

Rene