What are the best ab exercises to develop six pack abs? The answer to this question seems to be forever changing. For example, the sit-up has completely fallen out of favor by the fitness community. In fact, the majority of fitness experts now declare that sit-ups are incredibly dangerous to you spine. Where was this opinion born? Did countless trainees injure their spines from performing this “treacherous” exercise? Luckily for most of us, that is not the case.