Was watching the IAAF World Championships last night and noticed how some of the track athletes prepare for their race. Some portrayed this image of quiet confidence with no showmanship while others were really out there during their introductions. Then this brought the thought of how one of the world's best swimmers prepares for his races as well. If you notice whenever a swimming championship is on, Michael Phelps always has this sense of confidence in his mannerisms while he gets introduced to the crowd.
Same way as we train, we need to display a sense of confidence in the session. It puts you in the state of mind to also put 100% into your session because you know you can accomplish what you set out to do.