Stand with your feet hip width apart, holding a kettlebell in your left hand on the floor between your legs. Keep a neutral spine as you lean forward, bending at the knee and hingeing your hips back, all the while keeping a firm grip on the kettlebell on the floor. This is your start position. Keeping your core braced and hips still, pull your left elbow back and up towards your hips, bringing the kettlebell almost level with your left hip. Squeeze your back muscles as you do and exhale. Return the kettlebell to the floor with control. Repeat this movement on the other side. Keep alternating sides for the required number of reps (or time).