Reverse crunch with abduction
Loop a resistance band around your ankles and lie onto your back with a towel rolled up just underneath the natural arch of your lower back.
Engage your core – ribs down, and lift your feet up and straighten your legs, pressing them out into the resistance of the band and lifting the legs as high as you can while maintaining that natural arch of your lower back.
From here, maintain that engagement in your legs as you tuck your pelvis under, lifting your tailbone off the floor, holding that reverse crunch for a count of 5 if you can, then control the lower back to the start position, without losing your core engagement. Reset between each rep and repeat.