Athletes work towards the Olympics like Rio 2016 for years before the big event. They carry their own hopes and dreams, and those of their family and friends. They'll know that their entire country will be rooting for them and the world will be watching.
Talk about a high-pressure situation.
Even if you are at your physical peak and technically perfect, how you think can play a significant part in the outcome of a race. How will you cope with the emotional and psychological pressures and will your nerves help or hinder your performance?
BootsWebMD spoke to Dr Marc Jones, a sport and exercise psychologist at Staffordshire University.
"Athletes are individuals," he says. "For example in a race of eight people, each one of them may have their own different way of preparing."
Imagery: This is when the athlete mentally rehearses the event beforehand. They see themselves performing, imagine themselves feeling calm, collected and in control. They run over the event in their heads and think about how they will feel, and which movement patterns they will use in the event.
Distraction: The technique of distraction is popular with many top sportsmen and women. They may have a playlist of music that they listen to in the lead up to a big event to stop them over-thinking. Rebecca Adlington admitted to watching TV to help her prepare for her two Olympic swimming golds at Beijing in 2008
Internal dialogue: Some athletes talk to themselves before a big race or event. They may have an internal dialogue or they may say things out loud. They tell themselves to think in a smart way and try to talk themselves out of any self-doubt and push out negative thoughts.
Allow nerves: Some athletes who are nervous beforehand give into those nerves, let them all out and deal with them before the race or event. So when they get to the starting line or beginning of their competition they are free of worries and they have moved on.
The role of a coach
The relationship between a coach and an athlete is a very close one. It is physical and technical but also a large part will be psychological.
Athletics coach Fiona Darling-Glinski says on a basic level you can't underestimate the importance of a familiar face when athletes are taking part in bigger competitions.
"The unknown can be very frightening for the athlete and their confidence can take a real dip when faced with the competition. Unfamiliar surroundings and untried athletes can be a daunting prospect."
Fiona says: "Having a coach by their side can help to remind the athlete that they deserve to be here, that they have trained for this and that they are by no means on their own."
To provide even greater transparency and choice, we are working on a number of other cookie-related enhancements. More information