This weekend I was at home so I could not go out and socialize but I still got exercise in. I went out in the yard and played tennis agenst the garage. Using kinetic energy from my hand and transferring it onto my racket and then onto my ball then when it hits the garage door the energy gets reflected back at my racket and so on and so forth. I also ran around my house a few times. When you run the kinetic energy from your feet push agenst the ground making you run.