Worth it. Krishna Kumari 18 Days Yoga is a set of yoga courses produced by Qianchat Online School, which aims to help students improve their physical fitness, relieve physical fatigue, improve sleep quality and reduce stress. This course is divided into 18 class hours, each class hour is about 30 minutes, including basic yoga, advanced yoga, breathing exercises and so on. In addition, the course also provides detailed teaching videos and graphic materials to facilitate students to study anytime and anywhere.