Walk your feet forward until your body is at a 45-degree angle to the floor, arms fully extended and your body in one straight line. To make this harder on a TRX, walk your feet further forward so your shoulders are even closer to the ground. The advanced version of this would be to have your body almost parallel to the floor. To make it easier, walk your feet back so your shoulders are farther away from the ground.
With your core stabilized and your legs straight, with either your feet or heels planted on the floor, bend your elbows behind you, keeping them close to your body and pulling your chest toward your hands.
Straighten your arms to lower your torso, completing one rep.