Hi, I am 15 years old and I want to have leaner abdominals. My question is this: aside from doing crunches and situps, if I walked around flexing my abdominal muscles (just contracting and relaxing them or keeping them contracted for a while) without the crunches or situps, what kind of an affect would that give? Would it do any good or should I forget about it, because it does wear out my abnominal muscles when I do it. I would like more of a professional to answer this question please and if so what is your experience? Thank you!