Well, the real secret is in how many different exercises you do and how well you target each area of your stomach.
If the only exercises you’re doing right now consist of crunches or sit-ups, then you’re settling for a sub-par workout. Your abs have the ability to handle very high repetitions, but they also like to be surprised, just doing crunches and sit-ups alone won’t always do the trick.
So if you’d like to feel what it’s like to get a killer ab workout, then here’s a simple formula you can try.
The first step is to pick 7 different abdominal exercises — not just one or two. Each exercise should be unique and slightly different than the other 6 to the work different areas of your stomach. And dont forget your oblique muscles.
Since your abdominal muscles will peak and max out at 21 sets, all you have to do is repeat those 7 exercises 3 times. For each set, perform 25 repetitions or less of each movement to avoid overtraining those muscles.
I would suggest doing between 10 and 15 reps to get started (12 reps is what I prefer) The trick is to do all 7 exercises in a row first and then go back to repeat each of the 7 exercise in a row 2 more times with your desired number of repetitions.
It’s better to start off with a lower number of reps so you don’t hurt yourself as well.
Remember, this is the formula I use to get a killer ab workout, so make sure you approach it slowly at first, or you’ll definitely be sore the next day.