Many people may not know what a hemisphere, or speedball, is. It looks like a strange half of a "Yoga ball".
Fitness for health, but many fitness novice partners in fitness, often due to the lack of fitness knowledge, did not do the necessary preparation work and lead to physical injury, such as running a broken foot, the first time running a one-time run too long to cause knee pain and other phenomena. Experienced fitness people tell us that fitness is not only to have the correct posture, but also to prepare some of the necessary external fitness supplies. There is not a saying that "Fitness go, equipment first" It, hahaha.
What is the most recognized face muscle in the fitness world? Some people may say it is the pectoral muscles. There is a saying that newbies practice their pectoral muscles just because they get a lot of hair attention.
Yoga aids can make the posture more relaxed. Of course, in addition to using aids to simplify the pose. It can also make the poses more difficult or even make them more interesting.