BJJ, Judo, and Submission wrestling allow you to apply chokeholds to your opponent either using your arms, legs, or the gi. Occasionally this results in temporary unconsciousness. The time it takes to render an opponent unconscious depends on how well the technique is applied and various physiological factors.
There has never been a death reported in bjj or judo competition from a chokehold. The referee will signal a stop then the unconscious person will wake up in a relatively short period of time. Occasionally there are some tremors that might resemble the kind of shaking you get in your legs as you fall asleep and the person regaining consciousness will likely be confused for a few seconds as he begins to understand what happens.
The two biggest safeguards to prevent injury are:
1. Early recognition of unconsciousness – The instructor or the person applying the choke should keep a close eye on the actions of the person being choked. This is especially true if they are mounting a vigorous defense. If possible look at their eyes – unconscious people or those who about to go out get a ‘far-away’ and unfocused gaze. If they are defending strongly then suddenly stop or make loud snoring noises it could also be a sign that they are out. Let go immediately if you notice either of these. The instructor or referee should stop in as well at the first sign of unconsciousness.
2. Head/neck trauma – When releasing the chokehold it is possible that your opponent may fall over and hit his head on the mat. Support the person’s head and let them down easy to protect their head and neck. Many times the submission attack will leave you in an awkward tangled position. Call an instructor or teammate over to help you out of the position if necessary so you can protect your training partner.
The person will typically regain consciousness on their own within 15 seconds. If not then standard emergency procedures as per first aid/CPR certification should be initiated.
Here is a good article on the physiology of choking from another site.
This is a choke out highlights video so that if you haven’t seen a choke out before you know what to look for.
Brian Jones, PhD