This age is very good. Sanda is similar to waijia boxing. It doesn't need long-term internal force and practice, and most of them are fast-paced. Isn't it the same for soldiers like armed police? Generally, you can practice well in three years (reaching the basic level), and you can stretch ligaments in middle age. Don't worry about this. There are still some defects in Sanda in primary schools, one is lack of strength, and the other is hypoplasia of bones, heart and lungs, which is easy to get injured.