For your abs
For your abs, machine crunch rates well ahead on our research criteria: easier to progress, more of the work on the abs.
Hanging leg raise gives more stretch.
Both are good choices that train the abs the same way, so they swap freely. Rotating between them every few weeks is an easy way to vary your training.
The research score comes from these, scored by hand from the studies. Lifter scores appear once an exercise has 10 ratings. How scores work
Hanging Leg Raise. Curling the pelvis up trains the abs hard, but grip and hip flexors often end the set first.
Machine Crunch. Loaded spinal flexion on a fixed path, easy to progress like any other machine.
For your abs, machine crunch rates well ahead on our research criteria: easier to progress, more of the work on the abs. Hanging leg raise gives more stretch. Both are good choices that train the abs the same way, so they swap freely. Rotating between them every few weeks is an easy way to vary your training.
Machine crunch is easier: it’s easy to learn, while hanging leg raise takes some practice.
Hanging leg raise needs a pull-up bar, so a home gym covers it. Machine crunch needs a machine, so for most people it’s a gym exercise.
Machine crunch: it rates Excellent for joint and recovery cost in our research rubric, against Strong for hanging leg raise.