Rebounding is a low impact cardio alternative to running / jogging. Jumping has less impact on your bones and joints compared to running. The rebounding method helps those individuals with issues or strains in ankles, knees and hips. The "bounce" slows impact from the downward force storing it as potential energy, which is then released as kinetic energy to propel the jumper upward. The elasticated bungee cord acts as a suspension spring heavily reducing impact compared to dropping heavy steps onto solid ground. Keep cardio and intensity high, while keeping damage to bones, joints, tendons and muscles to an absolute minimum.