A "Vol 619" suggests a very long-running series, common in stock footage libraries, gymnastics training archives, or hobbyist magazines.
To become a skilled junior acrobat, one must undergo rigorous training and development. This typically begins with basic exercises and movements, such as tumbling, balancing, and stretching. As young acrobats progress, they learn more complex skills, including aerial stunts and partner acrobatics. They also work on building their strength, flexibility, and endurance through conditioning exercises and strength training. scdv28006 secret junior acrobat vol 619 link