Always remember, whether you think you "Can or Can't" you're right. Believing is Seeing. Also, instead of telling yourself that you're doing an "Ab challenge" tell yourself that you want to improve your health all around. Turn this into a lifestyle change and not just one single focus. ex, Instead of me saying "I want to gain or lose weight" I'm going to focus on also improving my sleep, diet, discipline etc, which will all translate into an improvement in multiple areas as well. Love the process and as long as theirs always positive growth, don't become discouraged when you're not moving at the same pace as the next person. You're in control!!