The vocalization is the action of muscle movements, including the vocal cords, and the vocal cords are composed of soft tissues.
Therefore, vocalization is really similar to and could be categorized as a sport.
Although the amount of time for practicing a sport varies from each person. The ideal time to vocalize is 45 minutes straight, after that take a break and rest for 15 minutes, then start vocalizing again for 45 minutes.
I tested how long is the best amount of time to vocalize, using the four different times and methods listed below.
1.Singing for 15 minutes and then taking a rest for 15 minutes (Repeated 12 times)
2.Singing for 45 minutes and then taking a rest for 15 minutes (Repeated 6 times)
3.Singing for 90 minutes and then taking a rest for 30 minutes (Repeated 3 times)
4.Singing for 150 minutes and then taking a rest for 30 minutes (Repeated 2 times)
6 hours later, 1 and 2 can display the same voice quality as before singing but 3 and 4 displayed a hoarse voice.
Especially 4. Which after the test, continued to have problems with the voice for few days.
As a result, I have concluded 2 is the best and ideal time for practicing vocalizing.