Is the lack of strength. Standing long jump requires high explosive power of leg and abdominal muscles. When you jump hard, you can also feel the tightness in your abdomen, and the back will hurt. Jump as high as you can, then quickly retract your legs with the strength of your abdomen and fold forward to land. Therefore, in addition to practicing leg strength, we should also exercise the strength of sit-ups and sit-ups to lift legs. Only when your legs are strong enough can you retract them into your abdomen as quickly as possible. Even if your legs are strong enough, it will affect many achievements. I am not tall, but when I was at school, my peers rarely jumped over me, just because I closed my legs quickly and fully. You have to lower your body down, close your legs and lower your center of gravity, so that your legs can take advantage of dozens of centimeters when you lean forward. When I fail in the standing long jump, I usually fall. At this time, I realized that it's not how amazing my jumping ability is, but because my legs are closed and I lean forward, accounting for dozens of centimeters at a time, so many tall people are not as good as me in standing long jump, but my running long jump performance is average because of my poor endurance and poor running coordination.