The fire hydrant in-out exercise increases flexibility and mobility throughout the core and hip regions. This movement functions as a warm-up to prepare the lower body for physical activity.
Get on your hands and knees on the floor, making sure to keep your knees and hands hip-width and shoulder-width apart, respectively. Your knees should be bent to 90 degrees, directly beneath your hips.
Brace your core and, without moving your hips, raise your right thigh out to the right side of your body, keeping your knee bent the entire time.
Without dropping your hips, straighten your leg backward so that it is in line with the rest of your body.
Return to the starting position to switch legs.
Avoid hyperextending or arching your lower back at the top of the movement. Keep your torso square and facing the ground throughout the entire exercise. The movement should occur at your hips.
Focus on contracting your glutes throughout the exercise.