From austerity, upon destruction of impurities, arises perfection of the body and senses.

Tapas purifies, and that purification (aśuddhi-kṣaya) results in siddhi (perfection) of the body (kāya) and the senses (indriya).

Impurities are not just physical dirt, but energy blockages, accumulated toxins, habits that weaken.

The heat of tapas—sustained effort, voluntary discipline—burns these impurities as fire refines gold.

The result is a healthier body, sharper senses, and the extraordinary capacities (siddhis) that the texts mention: resistance to cold and heat, subtle perception.

Tapas is not self-torture, but the conscious use of effort to transform matter and energy.