| Always perform this exercise in a controlled fashion. No sudden jerking motions! This exercise looks easier than it really is. The twisting motion will present more difficulty for beginners because it will require some upper body strength. If you happen to be a beginner, don't get discouraged if the exercise seems too hard. Instead, stick with it for a few weeks and you will most likely get stronger and be able to execute it easier. Another item to point out is that if you have a history of back injury, you are best advised not to do this exercise. This is due to the fact that the twisting motion may aggravate your (previous) back injury and may cause discomfort. There is no reason to risk pinching a nerve when you can choose from so many other core exercises that are just as effective as this one. Finally, this exercise can be done in a variation which involves strapping ankle weights on. The ankle weights will increase the level of difficulty. This is a good idea if you reach a point where you think the exercise is getting too easy. Thus, adding ankle weights will keep you challenged. | 
