World 100m final - a survival guide
It's the biggest just-under-10 seconds of your year. Eighty thousand people are screaming in the stadium, millions more watching around the globe. Alongside you are the fastest men in the world.
How do you deal with that dreadful pressure? What do you do to stay calm the evening before, how do you sleep that night and what happens when your arch-rival tries to intimidate you on the blocks?
Seeking answers ahead of Sunday's showdown in the Olympiastadion between Usain Bolt, Tyson Gay and the cream of the world's sprinters, I picked the brains of 2003 World 100m bronze medallist and 2004 Olympic 4x100m gold medallist Darren Campbell.
Darren, here in Berlin as an expert summariser for BBC Radio 5 live, was famous for making the absolute most of his talent and chances in the big finals.
"Whether you're the favourite or not, you'll all be feeling nervous," he says. "The difference between success and failure is being able to deal with the pressure."
Prepare the night before
"Be by yourself, turn your phone off, cut yourself off completely.
"At that point you have no friends. You need to collect your own thoughts, because when you step on the line for the semi-final and final, there's nobody with you.
"There's no point in keeping your mobile on. If you get a text, you might not read it, and if you do, you're not going to reply, because you want your mind free of negative thoughts. You might get a text that says, 'Keep your head up,' and you'll start thinking, Is my head down?
"It's an individual sport, and a major championships is when you realise that. On the circuit you might hang out with your compatriots, but at a big championships you're all fighting for the same bronze, silver and gold."
Don't think about your rivals
"Personally, I wouldn't watch any of the rounds at the stadium or on television. There's no need to see what your rivals have done in the heats, because at that stage everyone is trying to show off - 'I'm the king here,' or 'Look how relaxed I am'.
"All you want to worry about is what you're doing - and to trust all the training that you've done for the last nine months. If I did that, I would pull out my best performance."
Sleep only when you're ready
"I would go to sleep when I was tired. A lot of people try to have an early night, because they've got such a big day to come, go to bed at 9pm or 10pm. The problem with that is that you've programmed your body-clock to go to bed at 11 or 12, and then all of a sudden you're asking it to change.
"Go to sleep when your body is telling you that you need to sleep, rather than tossing and turning. If you go to bed two hours earlier, the reality is that you're going to toss and turn.
"Sometimes the night before a final I wouldn't go to sleep until 2am or 3am. The key is, how much sleep do you need to perform at your best? I needed seven hours sleep, so if I went to bed at 3am and then woke up at 10am, that was fine.
"The final isn't until the evening, so you if you get a nap in during the afternoon, that's happy days. I learnt to meditate and do self-hypnosis.
"If there was a problem, I was able to put myself almost into a trance to relax me. It sounds extreme, but it can be horribly tense out there."
Stick with your normal routine
"All you've got to do before the race is execute your warm-up, so that's not a bad place to be.
"You're concentrating on yourself. You have a set time you're going to do it over; if you're in a hot country it's slightly shorter, if it's cold it's longer.
"The warm-up for a major championships is always more intensive, because you have to make sure you're as sharp as you can be. There's no point in warming up like you're only going to run at 70%."
Stay strong in the call-room
"Now there are just minutes to go. When you go into the call room, you aren't allowed your headphones on, or your phone - and that's the beautiful thing. It's you, your thoughts and your demons.
"Maurice Greene used to stomp around the room, growling, making everyone nervous. It used to work - I would see people who were faster than me suddenly shrivel up and be watching him. You could see them thinking, Oh no...
"Now that's what sport is about. What do you have in your locker that others don't?
"I would lie there by myself with my feet up, humming to myself or singing, laughing like I was crazy. If you bow your head it's a sign of fear, so I would laugh. Then they would be thinking, what's he got to laugh about?
"I loved that. I read a lot of psychology books, and I was able to switch myself off totally, or just watch and laugh."
Walk onto the track with your mind calm
"If you're where you need to be, if your mind is where it should be, you don't hear the crowd. You've blocked out the noise. You're in your own little world.
"It's weird - it's like there's no-one there. You barely see the opposition.
"Probably the first time your heart should start to beat fast is when the whistle goes to signal tracksuits off. I would just glare to the end of the finish line, because that's where you're going - that's all you need to see.
On the blocks, have just one thing in your mind
"If you're in the final at a major championships, the only thought you need to have in your head is reacting to the gun. That's the only thing that's a variable.
"The track is always 100 metres, the blocks will be the same set-up that you've used all season, the people you're running against are the same as all year. The wind is the same for everyone.
"The one thing that varies is the gun - ie will the starter hold you for one second, two seconds, three seconds? Concentrate on reacting, and trust the rest."
When the gun goes, let instinct take over
"Sprinting is a subconscious thing. It's like driving - when you get in the car, you don't think, left foot down, change gear.
"Your phases should be programmed. You know when you're going to come out of your drive phase, when you'll be at top speed. It's only at 70m that you bring yourself back into the outside world.
"In the race itself, time actually seems to slow down."