(Swimming and boxing have a good deal in common - and one of the wonders of the modern world is that although I am sitting in a lounge at the Owen Roberts International Airport in Grand Cayman I have just pulled up an interesting reference from Wacquant, Daniel F. Chambliss's "The Mundanity of Excellence: An Ethnographic Report on STratification and Olympic Swimmers"...)
Anyway, here is my favorite bit, the meat of the book:
[S]parring is not only a physical exercise; it is also the means and support of a particularly intense form of "emotion work." Because "few lapses of self-control are punished as immediately and severely as loss of temper during a boxing bout" [ED. That is Konrad Lorenz], it is vital that one dominate at all times the impulses of one's affect. In the squared circle, one must be capable of managing one's emotions and know, according to the circumstances, how to contain or repress them or, on the contrary, how to stir and swell them; how to muzzle certain feelings (of anger, restiveness, frustration) so as to resist the blows, provocations, and verbal abuse dished out by one's opponent, as well as the "rough tactics" he may resort to (hitting below the belt or with his elbows, head-butting, rubbing his gloves into your eyes or over a facial cut in order to open it further, etc.); and how to call forth and amplify others (of aggressiveness or "controlled fury," for instance) at will while not letting them get out of hand.
To learn how to box is to imperceptibly modify one's bodily schema, one's relation to one's body and to the uses one usually puts it to, so as to internalize a set of dispositions that are inseparably mental and physical and that, in the long run, turn the body into a virtual punching machine, but an intelligent and creative machine capable of self-regulation while innovating within a fixed and relatively restricted panoply of moves as an instantaneous function of the actions of the opponent in time. The mutual imbrication of corporeal dispositions and mental dispositions reaches such a degree that even willpower, morale, determination, concentration, and the control of one's emotions change into so many reflexes inscribed within the organism. In the accomplished boxer, the mental becomes part of the physical and vice versa; body and mind function in total symbiosis.