On your knees, pass the band behind your back above your glutes, holding its ends against your palms. Bring the band under tension straightening your arms in front of you and laying your hands on the floor.
Maintaining your arms straight and your abs tight, bend your legs toward your chest alternating or in a continuative way.
Core section (abs)
15/20 flex/extantion alternating per 3 sets.
Arching your back or let your hips “collapse” toward the ground while performing.