A good read about how even the very best swimmers get nervous before important competitions, but manage to channel that energy into best efforts
Being a little nervous is an advantage, not a disadvantage. This is what nervousness is for – to give you energy. Remember this in your next big race – channel the nerves into your swim, and feel your body unleash the incredible power it has been storing up for the race. Your mind will always provide what your body needs – and one of these things is nervous energy.