A lying reverse crunch with the feet pressing a Smith machine bar up as the hips curl off the bench. The guided bar lets you add load to the lower-ab curl.
Primary muscles
Secondary muscles
This information is general fitness guidance, not medical advice. Stop if you feel pain and consult a qualified professional.
Main muscles working (thicker lines)
Set a flat bench in a Smith machine, lie on it with the soles of your feet against the bar, unrack it with your legs extended and knees slightly bent, and hold the machine uprights.
Brace your abs and keep a slight bend in your knees.
Curl your pelvis up to lift your hips off the bench, driving the bar straight up with your feet.
Pause at the top.
Lower your hips back to the bench slowly, keeping the bar under control.
Breathing: Exhale as you curl the hips up, inhale as you lower.
Hips curl, legs stay fixed
Drive the bar straight up
Slow on the way down
Pressing the bar with the legs instead of curling the hips
Locking the knees
Loading more than you can control
Set the safety stops just below the starting bar height and rack the bar before you sit up.