Martial arts
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Nardole studied Tarovian martial arts for "a while". (TV: The Lie of the Land)
One of David R's interests was martial arts. (PROSE: Who Am I?)
Martha Jones knew martial arts, which she used on Syd in self-defence, and then on the Tenth Doctor for demonstration. (COMIC: Swarm Enemies)
Tania Chenka knew martial arts. (AUDIO: Snow)