How to Perform Knee to Chest Exercise - part of the women's fitness video series by GeoBeats. Hi, I'm Katie - trainer with Rockbody Bootcamp, Austin, Texas. I'm going to take you through an easy lower back exercise called the Knee to Chest. You can start on either legs. You're just going to bring one knee end towards the chest. Standing up nice and tall. This is going to help stretch out those very lower back muscles and also help you with your stability. You can hold there for 20 seconds. Gently release, and bring the left leg up. Hold that for 20 seconds and relax. And that is a Knee to Chest.