| Some people prefer to do this exercise without anything underneath their upper back. It's all about your own comfort level. Do whatever is more comfortable for you. To increase the level of difficulty, strap on some ankle weights and perform this exercise. Take a few moments to experiment and see if it feels better to perform this movement with or without a pad under your back. It pays dividends to spend a few moments to figure out what the most comfortable option is. This movement is a really good exercise for the core and it can be done by both beginners and those who are more experienced. However, your core will quickly get used to this exercise (within a couple of weeks) and you will need to challenge yourself by increasing the resistance level. To do this, as stated above, you can put on ankle weights or you can put a rubber band (anchored to a something heavy) around your ankle(s) and then perform the exercise. The latter option might prove to be more practical if you are at a gym since most gyms will not have ankle straps for you to use. If you are at home, it might be more practical for you to buy ankle weights than it would be to buy a rubber exercise band since you may use the ankle weights for jogging as well. | 
