Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to get a more flexible back [title] Try a bow pose. [step] While lying flat on your stomach, bend your knees so that your feet point up toward the ceiling and reach behind you to grab your ankles. Lift up with your arms and feet to feel a nice stretch in your shoulders and abs.

Ending1: [substeps] Hold the pose for 20-30 seconds, then exit the bow pose on an exhale breath. You may repeat the pose several times for better results. Ending2: As you get closer to the ceiling, bring the hands forward to give yourself a smoother back. [title] Do spinal twists to get a looser back. Ending3: Make sure your breathing is deep and steady, which helps ensure that your breath should not get trapped in your thigh muscles. [title] Push your butt back and keep your abs contracted. Ending4: [substeps] Hip flexors include triangle, teardrop, u, and crescent shape. Try to hold the pose for 20 to 30 seconds and then lower to the floor for 15-30 seconds.

Answer format: ending1/ending2/ending3/ending4