It should be called weight gain to be precise. If you want to gain weight, you should pay attention to the balanced exercise of all parts, because I have seen thin people practice muscles, but their arms are thick and thin and ugly. On the contrary, they have strong bodies and ugly arms, so they should practice in cycles.

The most important thing for thin people to gain weight is to pay attention to nutrition. After training, you should eat some carbohydrates and high-protein things (to put it bluntly, the simplest thing is a banana +4 boiled egg whites, not egg yolks), which will help you recover from excess.

No matter how hard you practice, it's no use keeping up with nutrition. I have a friend, 1.6 meters, very thin. He has been a muscular man for three years. Since he started exercising, he has eaten countless shrimps, chickens, fish and boiled protein every day. If he wants to gain weight, he can't save nutrition.

As for the abdominal exercises you mentioned, you can try a variety of exercises (you can find the complete abdominal muscle training action online), and you don't need to be limited to the abdominal ripper. Of course, getting started is still possible. After the block, you should carefully understand which action is to make the abdominal muscles in which area exert strength, and then look in the mirror more. If you feel that there is a shortage, you should train that area more. At this time, you often have to learn to practice the movements apart, instead of doing gymnastics at once like a primary school student.

There is a good saying that fitness starts with strengthening the body and strengthening the brain, and you can't practice a perfect figure by hard work alone.