Hi Marianne, Great question. You can certainly hold it longer – there is not a contraindication for doing so. However, the prime mover involved in raising the hips is Gluteus Maximus. Unlike the spinal extensors which are more static muscles and benefit from longer holds up to 10 seconds, the Gluteus Maximus are phasic muscles. They benefit more from increasing the load rather than the hold time. I encourage you to try the Active, Athletic or Elite level challenges.
Keep it strong!
Margaret

Hi Margo, Great question. The reason I do not encourage “rolling down” one vertebrae at a time is that the “rolling” action brings the spine into flexion – the same motion that occurs when you slouch or bend forward from your spine rather than hinging from your hips. The way I teach it keeps the spine in more extension and elongation.