To perform the hollow hold, lie on your back and extend your arms overhead. Straighten your legs with your feet together and toes pointed.
From there, tighten your core by drawing your ribs toward your pelvis and flexing your abdominal region.
Then raise your feet, legs, and shoulders off of the ground and flatten your lower back against the floor. Start with 3 holds lasting around 15–30 seconds each.
Throughout each hold, the only point of contact should be your lumbar spine region, roughly encompassing the bottom third of your spine from the tailbone to the mid-back area.
If you struggle to keep your lumbar spine on the ground, modify the exercise and start by keeping your feet planted on the floor and extending your arms toward your feet rather than overhead.