I am not a serious athlete, but I do like playing squash from time to time. What I mostly like about squash is that it is a game of strategy, where each player tries to build an advantage over multiple shots. First you get your opponent to run to the right, then you get them to run to the front left … and as the game progresses, they (hopefully) get behind the ball, their shots become worse, until at some point it is possible to finish the point! Of course when you are the one that runs from side to side and trying to get back into control – the game is much less fun.
Anyway, have not played for a while so yesterday when I played I was out of shape. But what was interesting was that I realized that my thinking ability was also diminished. Usually I try to plan my moves in advance, and think about where my opponent will move, what I will do next etc – but being out of shape made me think very myopically, and focus just on making the next shot. This of course was a very bad strategy and to my delight of my opponent I lost badly.
Perhaps the larger point is that being exhausted (and maybe also being under stress, physical exhaustion, sleep deprived, etc) makes people focus on the short-term and ignore the long-term – and this way become more susceptible to making mistakes….