In fact, people's most commonly used sit-ups have little effect on abdominal training and may also damage the spine. Many American troops have cancelled sit-ups from training because it has been found that sit-ups can lead to back injuries and pain or numbness caused by spinal cord compression. In contrast, crunching is more scientific and practical.

Target exercise site: upper part of rectus abdominis (upper abdomen)

Action essentials:

1. Pay attention to the difference between pull-ups and sit-ups: when lifting the body, the hips of sit-ups can't leave the ground, while pull-ups require that the lower back can't leave the ground, so the pull-ups are smaller than sit-ups, which is safe and reliable, and the stimulation to the abdomen is more lasting. Because the body is lifted more than 30, the back is basically not stressed.

The picture below shows the belly roll:

3. Some forms of abdominal tumbling do not lie flat:

(1) Recumbent belly roll: It can only be used if there is a certain abdominal strength.

(2) Roll the ball to the belly: pay attention to balance.

In a word, there are many kinds of tummy tuck. You can choose a few that suit you at any time, or do them in turn to adjust the fun of sports.