I don't know what kind of exercise it is, but it's hard to bend up when I'm upside down.

Belly rolling is mostly used for horizontal bar. Hold the horizontal bar vertically with both hands, then straighten your legs together, then slowly flatten the leg ends, and then lift your feet at a high angle until the root of your thigh exceeds the horizontal bar. The upper body wants to swing backwards, the lower abdomen hangs on the bar, and then leans back. Then put your body on the bar, your hands on the bar, and your lower abdomen. This action is called curling, which is the second one on the horizontal bar. The third exercise is to hold up the bar with two arms alternately, and the fourth exercise is to hang the bar on the leg. Swing your body first, hang one leg on the bar (inside your knee) when swinging back, and then ride on the bar by inertia. The fifth exercise is to swing first. When swinging forward to the end, the legs are straight like carp, but the legs are not bent, and the lower abdomen climbs directly on the bar. The sixth exercise is to swing the terminal forward, and the carp stands on two legs, and one leg is directly inserted into the bar, or inserted into the root of the thigh and directly rides on the bar. The seventh exercise is to pull up your body directly with your arms when you swing back to high, and climb your abdomen on the bar. The eighth exercise is to swing your body directly around the bar twice, with only two hands holding the bar. The common big circle in gymnastics is the circle. It's even harder to practice to 90. Generally speaking, it takes two months to do seven exercises. You should play horizontal bar for half an hour every morning, noon and evening, which is basically enough. You should practice running and sit-ups, and at the same time practice grip strength with a grip device. Beginners can tie their hands to the bar with a round broadband to prevent accidents. Wish you success!