Best Article on this Topic
I posted a thread about this article a few years ago. I am still a strong believer in differentiating between fear and anxiety. In case you don't feel like reading the whole article, it can be summed up by saying that in fear inducing situations, neurons relay impulses from your eyes to your your eyes to your brain, which in turn sets off an alarm to your hypothalmus.
As a result, the adrenal glands pump cortisol, norepineprine and epineprine. These stress hormones increase glucose production and heart rate, while speeing up your breathing. The good news is that these reations turbo charge your muscles, creating a fight or flight response that is actually beneficial to performance.
Researchers have found that anxiety has a different brain circuitry from fear. Anxiety can be descirbed as future oriented, with a concern for POTENTIAL threats. Anxiety produces a more low level of arousal, which is characterized by stiff muscles and increased pain sensitivity.
Here's the point I find really interesting: Anxiety stimulates cortisol, but not a significant amount of adrenaline! The result? The athlete feels paralized, and flow state is interrupted. Observe the person caught at the edge of the trail, afraid to make the first turn!
I will confess to self-plagiarism of my post on the original thread, which unfortunatelt turned into a ridiculous flame war. However, I was frequently posting about fear at the time. This year, fear and anxiety were more or less irrelevant... Probably why I got injured. A bit of both fear and anxiety can be healthy.