High Knees Lift is an exercise that combines the running motion with knee lifts. They are often used by runners and other athletes to improve running form as well as lower body speed, power, and flexibility. Perform high knees as a component of your warm-up or prolong the exercise and add them to your workout routine to really get your heart rate going. Great cardio exercise to get the heart pumping if performed regularly. It improves flexibility and power in the lower limbs.