1. Standing long jump is a sport to develop the explosive power and jumping ability of lower limbs. It needs the coordinated and rapid movement of the muscles of the lower limbs and buttocks, and cooperates with the swing of the upper limbs, so it also needs some flexibility. When jumping, your legs are slightly apart, your knees are slightly bent, your body leans forward, and then your arms naturally swing back and forth twice, and your legs are flexed and stretched. When the arm swings hard from the back up, the feet step on the ground quickly, the forefoot and knee joint are completely straight, and the hips stretch and jump forward. Push the body forward as far as possible, and the body forms a diagonal line in space. After crossing the highest point, the knee bends, the abdomen contracts, the calf stretches forward, and the arm swings back from top to bottom. When landing, you should land on the heel first, then bend your knees and lean forward.
2. Sit-ups are a form of exercise. Lie on your back, put your legs together, raise your hand, contract your abdominal muscles, lean forward with your arms, and quickly form a sitting position. Your upper body continues to bend forward, your hands touch your feet, and you bow your head. Then go back to the sitting position and continue to do it. Lie on your back on the floor mat with your knees bent 90 degrees and your feet flat on the ground. Don't fix your feet on the flat ground (for example, press your partner's hands against your ankles), or the flexors of your thighs and buttocks will participate in the work, thus reducing the load on your abdominal muscles. In addition, straight leg sit-ups will increase the burden on the back and easily cause back injuries. The position of your hands depends on the strength of your abdominal muscles, because the closer your hands are to your head, the more difficult it is to do sit-ups. Beginners can put their hands on their sides. When they adapt to or improve their physical fitness, they can cross their hands on their chests. Finally, you can also try to cross your hands behind your head, but put your hands on the shoulders on the other side of your body.
3. Sit-ups are a kind of physical exercise, and also a physical health test item for primary and secondary schools in China. The purpose of the test is to measure the possible range of motion of joints such as trunk, waist and buttocks at rest, which mainly reflects the development level of extensibility and elasticity of joints, ligaments and muscles in these parts and the flexibility of the body.
These are the answers to all the items in the physical fitness test.