CrossFit consists of constantly varied functional movements, such as pulling, pushing, squatting, running, and lifting, executed at high intensity. We do not use machines. Rather, we use kettle-bells, medicine balls, barbells, climbing ropes, boxes, pull up rig, and floor space for burpees, sit ups, running and jumping.
The workouts themselves are completely scalable. This means that anyone can complete the same workout with only the load and intensity varying. Whether you are in shape or want to get in shape, CrossFit will accomplish the goal.