Have you ever seen those people that do like 200 stomach crunches a day? But their crunches are super fast and only come up part way.
Well guess what. If you did one songs worth of ab exercises, at rhythmic pace, you'd get a much better workout. First off, when you take your time, you create resistance and use strength of muscle as opposed to momentum. Secondly, if you use about 3 different ab exercises in one song, you can exercise upper, lower, and side abs.
Next week, I will post my favorite ab workout that's helped me have a really strong core. For now just remember that it doesn't matter how many repetitions you do, if your form is off. You won't be working the right muscles or getting the most out of your time and sweat.