Which of the following is NOT one of the eight limbs of yoga?

The choice of Calisthenics as the answer is correct because it is not one of the eight limbs of yoga, which are foundational principles outlined in Patanjali's Yoga Sutras. The eight limbs include Yama (ethical standards), Niyama (self-discipline), Asana (postures), Pranayama (breath control), Pratyahara (withdrawal of the senses), Dharana (concentration), Dhyana (meditation), and Samadhi (state of bliss or enlightenment).

Calisthenics, on the other hand, refers to a form of exercise that involves a variety of movements that target large muscle groups and help improve strength, flexibility, and fitness without the use of equipment. While physical fitness is beneficial and can complement a yoga practice, it is not included in the philosophical and systematic approach of yoga as outlined by the eight limbs.

By understanding this distinction, it becomes clear how yoga encompasses a broader scope that includes physical postures (asana) and meditative practices (dhyana), as well as ethical and self-regulatory practices, while calisthenics remains a separate form of physical training.