Yoga Rahasya Chapter One verse 85

cikitsataḥ prāṇa-gatiṃ parīkṣya-ādau pravartayet |
rogiṇo deha-śaktiṃ ca na-anyathā phala-dāyakaḥ ‖

If engaging therapeutically, firstly
examine the gait of the breath
and the power of the body.
Otherwise it will not bestow fruits.

cikitsā - therapeutics; medical treatmentprāṇa - vital force; the breath of life; breath; inward airgati - going, moving, gait, deportment, motion in generalparīkṣā - inspection, investigation, examinationādau - from the first or beginning, at firstpravarta - engaging in, undertakingdeha - the bodyśakti - power, energy; ability, capability; strength; might, effort;ca - andna - no; not; nor, neitheranyathā - otherwise, in a different mannerphala - fruit; consequence, effect; result; retribution (good or bad), gain or loss, reward or punishment, advantage or disadvantagedāyaka - giving, granting, bestowing