Following on from last weeks article. I started to look at some of the discussions that may shed light on why periods of high stress (academic or otherwise) can lead to increased injury risk. Now there are a number of physiological mechanisms that change when we are under stress. But we are not going to speak about these specifically here. An area that I also came across that I do not know is completely related but appears to potentially have some links is the findings of Samuele Marcora and how mental fatigue causes reductions in performance, with the majority of his work targeted at endurance sport.
If we look at Marcora’s work, he has consistently shown that if you give subjects mentally fatiguing tasks and then go on to ask them to complete endurance activity they consistently and reliably report that the task is harder (higher rating of perceived exertion). They will tell you that the task multiple points higher on a rating scale (such as a Borg scale) and this even appears to occur independent of the physiological outputs. That is to say that if they measured some of the physiological outputs such as contractile function, lactate production etc. So if we can still have the same physiological outputs, why would performance go down?
Well to tie the performance decrement with the rating of perceived exertion data, we need to lean on a theory known as the central governor theory. This theory suggests that prior to tasks we decide (often unconsciously) how much effort we must put into a task given our current capability and particularity with endurance tasks, we pace ourselves to reduce the risk of reaching complete failure.
Now although this theory is still debated it starts to match the two areas together. If our perception of the difficulty of a tasks is such that we find it difficult we will unconsciously reduce the output that we will voluntarily generate. While this remains to be proven conclusively the evidence does suggest this may be possible. So based on our discussion regarding academic, emotional or work stress in our last article, there is a very real possibility that when you see a decrement in your performance that does not appear to be physical, its very likely that you are suffering from mental fatigue that is shifting your perception of effort and changing your output.
In our next article we will look at ways in which we may be able to train mental fatigue factors and input behaviours that reduce their impact on your ability to perform your best.