Think back to when you were a kid.
Life has changed a lot since I was a child. In school, we had calisthenics (jumping jacks, toe touches, windmills, eraser races (eraser on your head, run back and forth), etc;after school it was rope swings on tree branches, trips to the pond where you caught frogs, or squished your toes in mud, crawling through bramble trails, backyard sandboxes, places to ride your bike and skate (remember the rumble of the concrete through the bottom of your skates?) Sure, we got hurt, but we figure out how NOT to get hurt.
Since those things are not always available and everyone thinks you're a lousy parent if you actually let your child get a scrape on his knee, we:
Have one area of our yard where we make mud holes.
When my son cannot concentrate, we do 20 jumping jacks, or toe touches or windmills.
We play follow the leader.
He grabs my shoulders and I hold him under his arms and swing him around (took a while to to find a combination that did not hurt either of us)
Wrap his blanket around him so he's a burrito.
Made a platform swing (2 foot by 4 ft) and hung it on the swing set. He can stand on one side, and his friend can stand on the other and they swing back and forth, or he can swing by himself (this is a parent supervision activity)
He has a exercise ball that he bounces up and down on when he gets exited during a movie.
A balance board for when I read him stories. He balances back and forth.
A Wii. The Wii fit balance games are beyond wonderful.
Wheelbarrow runs (he's the wheelbarrow and I hold his feet and we go through the house)
Take his towel and rapidly rub his hair after a shower, while going BBBBBRRRRRRRR with my lips.
Give him a punching bag.
those pool noodles, and whack each other with them. Stand on a 4x4 that has been stabilized in the grass and try to knock each other into the "lava pit" (the grass)
Arrange step stones all over the yard and jump from stone to stone.
Set up and obstacle course all over the yard (or house). I personally don't care if my children walk across my couch, as long as they are careful and not wearing shoes. We have 2 ft x 2 ft flat cushions we use the same as stepping stones or for hopscotch indoors.
Play "Mr. Magoo" tag (close your eyes and have the other players wear bells)
A mini trampoline worked well.
HyperDash and HyperSlide are GREAT toys.
Hikes. All over. Hours, sometimes. It really works, especially up and down small hills.
Bike rides. Same as above.
White noise machine. My son loves the ocean.
Bringing the laundry out. Bringing the laundry in. Matching socks (fun game! We mark our white ones with different designs in sharpie when we first get them)
Garbage can race (one wheeled garbage can, one wheeled recycling can-who can get it back to the storage space first, then run inside and tag "base")
Remember, it depends on the age of your child and their abilities, as well as your ability/desire to participate. We find if we do these things on a regular basis (basically, just let them PLAY, like we used to do before two hours of homework a night) he does better. Too many computer games does my son in, but he needs a little time on them because he feels he is good at them. If I leave him home with his dad and they do 6 hours of computer games, watch out! (only happened twice-never again) Does not happen with the Wii, but we only have active games, where you have to participate.
Hope this helps someone.