Yoga for Christians

I once had someone initiate a conversation with me by saying, "you know what's wrong with your religion? It doesn't incorporate any physical exercises into it like yoga." And I suspect that this criticism is something that many people, including Christians, would find persuasive and why they might be attracted to something like Yoga or why they might want to embrace a kind of syncretism between yoga and Christianity. Jesus told us to seek first the Kingdom of God and live righteously and all the other things that you might want will be added to that priority. CS Lewis put it this way. He said "Aim at Heaven and you will get earth 'thrown in': aim at earth and you will get neither." If you seek after God and the virtues he can instill in you by fidelity to his commandments and the infusion of His grace, then all the other goods will be more accessible to you. But if you chase after those things apart from God, they will slip through your fingers and you won't even know why. So why isn't physical exercise a requirement in the practice of Christianity or something that is emphasized within the teachings of Jesus or scripture?