The outcome of years of training will come down to just a few days, or even moments, in these next few weeks -- all of it watched closely by billions of people worldwide.
As well as being in absolute peak physical condition, every athlete will need to be in just as good condition mentally -- or psychologically -- in order to handle the multitude of pressures awaiting them. CNN asked top sports psychology experts to reveal just what it takes to perform well under pressure -- and, more important, win.
Ignore the competition
"Focus very much on yourself and your own abilities rather than people too much," said David Fletcher, senior lecturer in sport and performance psychology at Loughborough University. "You have to be very preoccupied with your own performance, almost bordering on obsessional."
This may sound strange because sport is all about beating the competition, but Fletcher insists that it's better for athletes to focus on themselves rather than compare their efforts to others: "Michael Phelps, the most successful Olympian in history, has been beaten. If he put too much emphasis on coming first all of the time, then that would crush him."
Set achievable goals
Motivation is a key psychological factor: "If people feel like they're good at something, then they're going to do it more," Fletcher said. The implication for athletes and coaches is to set lots of different achievable goals, he says. If all goes to plan, the athletes soon feel like they're improving.
Embrace the butterflies
Most people find butterflies in their stomach unnerving before important events, but they're actually a good thing. "These nerves that you're feeling are a sign that you care about this and you're ready to perform. You're psyched up, ready to go," Fletcher said, adding that it's about "interpreting those nerves in a positive direction."
Connect your brain with success
According to Fletcher, some athletes can learn to trigger a feeling of success through smell and sound alone -- outside of competitions. For example, when some athletes are feeling in a really strong, powerful state during training, they smell lavender oil and listen to a certain song. They then repeat these steps before competitions to bring back those powerful feelings.
"It can actually elicit quite strong emotions," said Fletcher, explaining how connecting to these neural pathways can help trigger the unconscious brain, pushing the athlete into a really positive state of mind.
"My main advice would be for the athlete to understand themselves better," said Andrea Faull, a sports psychologist at the University of Worcester. "Understand what they need to do to perform at their optimum level when it really counts, when the spotlight is on them."
For example, when Faull works with athletes such as Great Britain's wheelchair basketball team, she believes it's vital to help them understand what makes them tick and what they need to do to thrive under pressure. By doing this, they will discover their optimum mind set.
Talk to yourself
Many athletes have rehearsed scripts that they say in their minds to keep focused, Fletcher said. "[They're] convincing themselves and reminding themselves of things they've done successfully in the past. Because often, when the nerves hit, you start doubting yourself."
Recalling great training sessions, race times and hours dedicated to honing certain skills can combat negative thoughts creeping into an athlete's mind when under pressure. For example, top tennis player Andy Murray often leafs through a notebook during his tennis matches to remind him that he's prepared, capable and ready to win.
Learn to communicate
"All too often, conflict and miscommunication can derail things as you're preparing for major competitions," Fletcher said. As a result, many top athletes are very good communicators, so they can get the most out of their training with coaches and teammates.
It's also an element that can be controlled: For example, a short basketball player may not have the height to slam-dunk, but if they're a good communicator, they can bring the best out of the team -- and perhaps get someone else to do the dunk.
Ask 'what if?'
Being truly ready for a big sporting event means never being caught unaware. Just knowing what to do if your shoelaces snap, if your goggles break or if your cap comes off could give athletes the confidence needed to win, Faull said.
'Get in your bubble'
"I use the analogy of a bubble a lot with my athletes," Faull said. "You want to be inside your own little bubble; you don't want to let anything that might be outside of that bubble penetrate it or burst it."
This means sticking to routines, focusing on what needs to be done to perform and shutting out anything irrelevant to the task at hand.
Visualize the event
Athletes often need to get their mind into a state of readiness in order to calm their nerves and to feel in control of their bodies. "Visualization or imagery techniques is when athletes spend time essentially closing their eyes and picturing the race," Fletcher said.
A key part of competition is the "ready room" before athletes go out and compete. This is when all the finalists are bunched together in one place. They can hear the crowd outside, the loudspeakers, the commentators. The atmosphere can be electric, so it's important for them to be ready and visualize the moment beforehand.
Stick to the plan
"It's about having confidence in the plan," Faull said. "A lot of times, people are thinking in terms of the score or the time, but actually, if you stick to the plan and stick to the process, then the outcome takes care of itself." She believes the key is not to panic if you fall behind in the competition, just focus on yourself and the plan you practiced. It's the best way to perform well.
Pressure is a privilege
Pressure is often interpreted as being a negative thing, but it could actually be the opposite, says Faull. Many people -- whether top athletes or office workers -- really thrive under pressure, needing deadlines to get work done. "It's about teaching athletes to embrace pressure, see pressure as a privilege. ... You can interpret it as being your body's way of saying 'this is important to me. I feel ready.' "
And ... relax
Though embracing the butterflies and pressure can be a good thing, it's also important to not be totally overwhelmed by them. "We use relaxation techniques where people focus on their breathing and just keep a lid on some of those nerves," Fletcher said.
So the key is to be calm, pressured, and nervous all at once -- easy right?