Sense of Danger
I was wrestling with my good friend and housemate B--an enthusiastic Brazilian Jiujitsu practitioner--yesterday. The experience was incredibly mentally and physically exhausting. The source of the physical exhaustion was clear--I didn't know where to apply my energy and tried to apply it everywhere (my housemate told me as much). The source of the mental exhaustion was much less clear. I've done lots of competitive, quasi-combat sports in the past, most notably fencing and its backyard analogue with padded swords (sometimes called "boffing"). All day tournaments or long Capture the Flag battles typically left me energized, not drained.
B's mode of attack was to scoot forward constantly from a sitting "guard". In this initial, outer distance stage of the conflict, he would try either to wrap his legs around mine, or grab my wrist and try to control my arm. I had no comparable objective, since I didn't know what I was doing. So often the fight would degenerate into me backing away just quickly enough to avoid B's attacks.
When we actually engaged, again most of my energy would be spent defending against attack patterns I half understood, but could not implement. At one point I reached an advantageous position where I had his arm behind his head, and tried to use my other arm for a choke.But I couldn't finish it and, while trial-and-erroring different choke ideas, was also frantically defending B's many clever attempts to escape.
In this context, mental exhaustion appears to derive from the knowledge that something is Out to Get You--you must act, or Get Got. This leads to a Sense of Danger that will not permit you to rest. The presence of an entity who is acting adversarially towards you is only one of many things that yield a Sense of Danger--an impending deadline will do. I'm finally getting a glimmer of intuition into the feelings of those who don't enjoy casual competition--they have enough Senses of Danger active in their ordinary lives, that the idea of adding another for fun sounds masochistic.
This leads to a couple of questions. First, under what conditions is casual competition not masochistic? It has to do partially with the context. If you can't drop external Senses of Danger then you will be loath to add more. The timescale over which danger must be avoided is also really important. In long games of chess, senses of danger regarding weak points in your position build over long periods of time and generate terrific amounts of stress. Blitz chess is much less stressful because the Sense of Danger is active over a short period of time. In games like ping pong where at a low level each hit is almost independent, the Sense of Danger drops to background levels. Another factor has to do with the actual danger involved! Facing a higher level opponent who has more weapons at his disposal usually results in a greater Sense of Danger.
Second, how can Senses of Danger be mitigated? There are two main ways I am aware of: maximum loss guarantees and a countervailing Sense of Opportunity. One of my favorite techniques, the "Leroy's Blessing", deserves a 30 minutes of its own, but the basic idea is to set aside a fixed chunk of time for a given activity where one is permitted to ignore non-activity-related Senses of Danger. This is a maximum loss guarantee technique--at most, you'll lose an hour you could have had to deal with the danger. The countervailing Sense of Opportunity, I think, is what makes competitive games fun. You hope to make your plan work on your opponent, and nurturing your plan against your opponent's defenses is extremely satisfying. Maybe this is a personality thing--maybe for some people, defeating the Sense of Danger with appropriate countermeasures is the main event, and finding opportunities is a sideline. For me, defending against danger is a necessity required to keep the search for opportunity open. This is probably the biggest reason jujitsu is (currently) so exhausting for me--I cannot yet see the opportunities, so the Sense of Danger takes up my entire field of view.