According to the ancient text book s of yoga,
“Perfection of hatha yoga is achieved when there is leanness of the body, tranquil countenance, manifestation of the inner sound, clear eyes, diseaselessness, control of bindu (semen/ova), active digestive fire and purification of nadis. Hatha Yoga Pradipika II:78
In simple words, when the body becomes lean, the face glows with delight, the eyes are clear, and the body is healthy, one should know success in Hatha Yoga is approaching. II:78
HARI OM TAT SAT