Exercise #1: Fire Hydrant In-Out
Get down on your hands and knees with your palms flat on the floor and shoulder-width apart. Relax your core so that your lower back and abdomen are in their natural positions. Without allowing your lower-back posture to change, raise your left knee as close as you can to your chest (your knee may not move forward much). Keeping your left knee bent, raise your thigh out to the side without moving your hips. Kick your raised left leg straight back until it’s in line with your torso. That’s one rep.