But sit-ups are not suitable for beginners.

Because the correct sit-ups are too difficult, most people can rarely do them.

What is right? The posture of 1 is correct, and the legs are bent 90 degrees, otherwise it will cause great pressure on the spine.

2. Inertia should be avoided in any basic training, that is to say, when we do sit-ups, we should get up gently, fall gently and stop at 1 sec for 2 seconds, and you may find that we can't do it at all.

It is particularly important to note that sit-ups as a core strength exercise, if you rely on inertia for a long time, will definitely cause the deformation of the body's center of gravity, and finally even the bones of the whole body may be deformed.

In fact, the trump card for exercising abdominal muscles is leg lifting. You may not even have heard of it. But think about the athletes who performed Thomas at the Olympics. Yes, that action requires very strict abdominal muscles.

Specific exercise methods can be found in the book Prisoner Fitness. There are pictures and articles on the internet, which are very detailed.