I was envolved in Chi-Kung for years prior to becoming a Christian.
I saw some pretty mindblowing feats of matrix-like supernatural strength and motion in teachers that were very skilled (effortlessly moving cars, throwing people across the room with soft hits, etc.) that were definitely relying on a source outside of their own physical being.

I wouldn't say martial arts is a 'cult' . Though it forms more of a New Age Eastern meditational spirituality in some.
With all the talk of absorbing and harnessing chi, or 'energy', at some point it clicks in a Christian that you're allowing your soul to be open and have entrypoints to some dark spirits.

Prior to being delivered from a spirit of witchcraft I let in through my meditation, I could 'harness power' to effortlessly stay awake for days on end that came in handy when I needed to be productive.

Though I don't think we can completely destroy the benefits of martial arts. You can be envolved in the martial arts as long as you steer clear of the pagan Eastern religion practices.