The Bhagavad Gita · Chapter 2 · verse 2.48
Established in yoga, perform action, having abandoned attachment, and remaining even-minded in success and failure. Evenness of mind is called yoga.
Sanskrit (Devanagari)
योगस्थः कुरु कर्माणि सङ्गं त्यक्त्वा धनञ्जय। सिद्ध्यसिद्ध्योः समो भूत्वा समत्वं योग उच्यते॥
Transliteration
yoga-sthaḥ kuru karmāṇi saṅgaṁ tyaktvā dhanañjaya; siddhy-asiddhyoḥ samo bhūtvā samatvaṁ yoga ucyate
English translation
Established in yoga, perform action, having abandoned attachment, and remaining even-minded in success and failure. Evenness of mind is called yoga.
Meaning — what the verse is actually saying
The Gita's definition of yoga is not posture; it is equanimity. The same person, in success and in failure, is the yogi.
Modern practice — what to do today because of this
After any outcome — win or loss — pause for thirty seconds before reacting. The pause is the yoga. The reaction is what comes before yoga. Over months the pause widens. Over years it becomes who you are.