Glute Bridge with March
Bend your arms to 90 degrees and then drive through your arms, upper back and heels to bridge up. Squeeze your glutes and brace your abs to bridge up.
Holding this bridge, lift one foot up off the ground, bringing your knee in toward your chest as if marching. Do not let your hips sag as you lift the leg.
Move slowly to lift the leg then lower back down and switch, bringing the other knee in toward your chest.
Do not let your hips sag as you march. Also, do not let your low back take over. Keep your abs engaged and really focus on making the glute of the leg that is down work to keep your hips up.
You may not want to lift your leg as high if you struggle to maintain the bridge. Doing a smaller march means that each side has to work independently for shorter, which can make the move a bit easier.