Originally Posted by
Echo
There is an optimal arousal level for all activities. The arousal level for the hundred meter dash is different from the arousal level for shooting, and those are both different from the optimal level for golf. Practice, and good coaching, can cause a marksman to approach that optimal level, and their pulse rate, and concentration, &cetera, will work toward the best score.
And deep breathing is part of a technique for reducing anxiety, that reduces arousal, and pulse rate is attendant with that.
At Perry many years ago there was a team member who was known to be tightly wound (helicopter pilot - what would one expect?). He would get visibly upset when he shot a 7, for example, and slam the shooting bench. That 7 was history - he might have been better served to dial it back a couple of notches and concentrate on basics, rather than expend resources on history. He was hoping to be the first Academy graduate to break 2600. He didn't make it. His 'resting' arousal level was fairly ideal for being a helicopter pilot. But he couldn't dial it back to the level necessary for top competition.
YMMV...