Thanks for your question!
Why would you want to study self defence? Are you expecting to defend yourself by physical force? Is this how you understand Christ?
Who was more worthy of being physically defended than Christ?
Peter tried it
John 18:10,11 Then Simon Peter having a sword drew it, and smote the high priest’s servant, and cut off his right ear. The servant’s name was Malchus. Then said Jesus unto Peter, Put up thy sword into the sheath: the cup which my Father hath given me, shall I not drink it?
Matthew 26:52 Then said Jesus unto him, Put up again thy sword into his place: for all they that take the sword shall perish with the sword.
Luke 22:51 And Jesus answered and said, Suffer ye thus far. And he touched his ear, and healed him.
Pilate gauged Christ’s innocence by it
John 18:36 Jesus answered, My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence.
Did Christ practise what he preached?
Matthew 5:38-48 Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth: But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also. And if any man will sue thee at the law, and take away thy coat, let him have thy cloke also. And whosoever shall compel thee to go a mile, go with him twain. Give to him that asketh thee, and from him that would borrow of thee turn not thou away. Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy. But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you; That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust. For if ye love them which love you, what reward have ye? do not even the publicans the same? And if ye salute your brethren only, what do ye more than others? do not even the publicans so? Be ye therefore perfect, even as your Father which is in heaven is perfect.
Matthew 10:16 Behold, I send you forth as sheep in the midst of wolves: be ye therefore wise as serpents, and harmless as doves.
Paul writes to the Romans
Romans 12:19 Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord.
Did Paul practise what he preached?
1Corinthians 4:12 And labour, working with our own hands: being reviled, we bless; being persecuted, we suffer it:
Paul writes to the Philippians
Philippians 2:15 That ye may be blameless and harmless, the sons of God, without rebuke, in the midst of a crooked and perverse nation, among whom ye shine as lights in the world;
Paul writes to the Thessalonians
1Thessalonians 5:15 See that none render evil for evil unto any man; but ever follow that which is good, both among yourselves, and to all men.
James 5:6 Ye have condemned and killed the just; and he doth not resist you.
1Peter 2:21-23 For even hereunto were ye called: because Christ also suffered for us, leaving us an example, that ye should follow his steps: Who did no sin, neither was guile found in his mouth: Who, when he was reviled, reviled not again; when he suffered, he threatened not; but committed himself to him that judgeth righteously:
1Peter 3:9 Not rendering evil for evil, or railing for railing: but contrariwise blessing; knowing that ye are thereunto called, that ye should inherit a blessing.
If we aspire to follow Christ and his teachings why would we need to study self defence? Self defence is a euphemism for retaliatory attack. Would we not do better to study self sacrifice and leave our defence in the hand of God?
I hope this helps,