I don't mean to change the subject, such as it is, but I feel the need to complain about the head gear in boxing, kickboxing, and similar sports. It protects against bruises to the outside of the head, caused by simple impact, but doesn't do nearly enough to protect against bruises to the brain cause by rotational accelerations.
Basically, the way people are killed by these blows is that the skull is violently rotated, causing it to slam against the brain, or if you prefer, the brain is sloshed around inside the cranium by cranial rotation. That causes internal hemoraging, stroke, and death.
There are age-old fixes to this problem, such as the way medieval jousting helmets were firmly bolted to a knight's chest plate, preventing rapid rotations in any plane, or the neck supports used by NFL linebackers to transfer loads directly from the helmet to the shoulders, bypassing their massive necks as 'not thick enough'.
An additional benefit of locking the head to the chest is a reduction in long-term, cumulative brain injury.
Sure, it would reduce the participants' freedom of head movement, but we can move our eyes in our sockets and could even compensate by surrounding the head gear in a crown of iPhones that bluetooth video data to the boxer's eyes.
In any event, I would assume that women are more likely than men to die in kickboxing since they have very good leg strength, greater flexibility for delivering head kicks, and less muscular necks (I doubt that even wildly athletic women want to look like a 'neckless' linebacker).