Roman Chair Leg Raise: 4 sets of 50 reps.
I worked my way up to this point, no shame in starting at a lower number of repetitions.
This is my current go to: I started at 4 sets of 25 reps hanging leg raises, which can be used as an alternative if your gym lacks the equipment to do this.
Hanging Leg Raises:4 sets of 25 reps.
This is what I was doing prior to the roman chair leg raise. If you are using this as an alternative feel free to flex the number of reps, more or less as you are comfortable. If you get super comfortable, you can also add weight accordingly.
Lying Leg Raises: 4 sets 25 Reps.
This variation is a great alternative for when you don't have anything to hang from, again, feel free to do more or less as you see fit and add weight- just be sure you have a secure way to grip the weight to avoid injury.