Important stabilizers: Rectus Abdominis, Obliques, Quadriceps
Stand holding an ab wheel using a pronated (overhand) grip.
Flex your hips and lower the wheel to the floor in front of your feet.
Lean forward a little so that the ab wheel supports your weight.
Keeping your elbows slightly flexed, inhale as you slowly roll out as far as you can without allowing your lower back to sag.
Hold for a count of two.
Exhale as you slowly roll back in to the starting position.
Comments and tips
The standing wheel rollout is an advanced core exercise. Before you attempt it, you should master the walkout, the front plank, and the wheel rollout on your knees. Other exercises that can help you to safely progress to the standing ab wheel rollout include the stability ball rollout on your knees and the standing stability ball rollout. To learn safe progression, watch the first video.
If your lower back sags when you roll out, it means that you are rolling out too far. Reduce the distance to which you roll out. Gradually increase the distance to which you roll out as you get stronger and are able to maintain a natural curvature of the spine.
Your rectus abdominis, along with your obliques and quadriceps, act as important stabilizers for this exercise. As such, these muscles are exercised isometrically, not dynamically as are the synergistic and target muscles.
To make the standing ab wheel rollout more difficult, try rolling out in different directions. You can also load with a chain or a weighted vest. See second video.