To some extent, this is right, but if you want to build six or even eight angular abdominal muscles, it has a lot to do with body fat. If your body fat rate is not low enough, no matter how you practice, your abdominal muscles will not show up.
Therefore, whether the diet is reasonable is a key to the development of abdominal muscles. At the same time, necessary aerobic exercise, such as running, can also help you lose body fat and exercise your abdominal muscles.
Secondly, the breathing state during training is also the key factor of abdominal muscle training. Only by adjusting the breathing state and changing the movements to match the rhythm of breathing can the best training effect be obtained.