Tetherball
Many parks and playground areas have tetherball. Tetherball is a game that involves a ball connected to a pole by a rope. Eight year old boys can enjoy punching the tetherball around the pole to see how fast they can get it to wind all the way around, or they can play against other kids at the park to see who can wrap the ball around the pole first. This game does not involve running, but it does require hitting or punching the ball, and sometimes jumping if the ball swings up high.
Monkey Bar Race
Playgrounds that have monkey bars inspire competitive races in young boys. Eight year olds who love to climb and swing will appreciate a monkey bar race against other kids on the playground. The goal of a monkey bar race is to swing your way across the bars the fastest, without dropping to the ground. Variations of the game include skipping bars so that you swing from every other bar.
Tag
Tag is a classic park game that kids around the age of 8 enjoy to play. The game involves running around and trying to escape the person who is It. Home base is established near a tree or bench at the park, It is your child's safe spot, where he cannot be tagged by the It person. If he is tagged, he becomes It and then has to tag somebody else. This game requires a lot of chasing, but is fun for your 8 year old and will tire him out by the end of a day at the park.
Basketball
If the park has a public basketball court for kids to play on, your 8 year old might be eager to shoot hoops with some other guys his age. Many 8 year olds already know the concept of basketball and enjoy bouncing, aiming and shooting balls with friends. If the park has an age-appropriate basketball hoop, then take your son to that court as opposed to the regular-sized hoop that is much taller and intended for older players. You will likely have to bring your own basketball to a public park.
Obstacle Course Challenges
Eight year old boys have vivid imaginations, and it is likely that when your son gets together with others his age, they will come up with obstacle course challenges to do in the park. A park obstacle course might include racing from a starting line to the jungle gym, swinging across the monkey bars, sliding down the slide and racing to the finish line. The boy who completes the challenge in the least amount of time wins.