Cardio equipment improves heart and circulatory system health while remaining geographically static. Treadmills allow users to continuously walk or run for a desired amount of time. Elliptical machines provide low-impact exercise and mimic the body mechanics of cross-country skiing, walking, and stair climbing. Exercise bikes provide low-impact pedal-driven cardiovascular physical activity. Plyo training boxes and training hurdles focus on jumping motion to generate short bursts of exertion, activating fast-twitch muscles in the legs and core.