This Sunday, runners from across the UK will gather for the event they've spent months training for – the annual London Marathon.
If you're one of the fit few who has decided to take on the challenge (not to mention who managed to get a much-coveted place), the next three days' preparation will be crucial. Here are six ways to make sure the run goes smoothly as possible - and to help you achieve the best time you're capable of.
Eat foods you're used to (and stay sober)
If you go out to a restaurant on Friday or Saturday, don't be adventurous with your choices from the menu. A healthy digestive system is key to a strong sports performance, so go for something you've had before and know won't make you feel, er, a bit funny.
Alcohol is, obviously, a no-no if you want to do well on Sunday.
Practice makes perfect, but not just before a big race. With three days to go, your muscles need to mend themselves from all the other training you've put them through, and training too much just before the event will exhaust you so much you won't do your best. Give your body a break, and it will thank you on Sunday.
Drink lots of water
It's obvious that you'll be guzzling water on the big day, but staying hydrated beforehand is also important. As a guideline, try and drink at least two litre-sized bottles of water every day for the next three days.
Stretch, stretch, stretch
To work properly during a 26-hour race, your muscles need to be relaxed and ready to take the strain - so make sure you stretch a couple of times a day in the run-up to the marathon. Concentrate particularly on your back and hamstrings by trying to touch your toes and holding your feet up against your bum (one at a time, of course).
Go to bed early every night
You may have a night out with friends scheduled over the next few days, but make sure you leave early enough to get a good night's sleep. Don't mess around with your body clock this close to the event, or you might have trouble sleeping on Saturday night, which will definitely affect your time in the race.
Leave time between breakfast and running
You need fuel inside you to run a marathon - but it's a bad idea to start running on a full stomach.
A sensible time to have breakfast on Sunday is two hours before you start running. If you're having trouble deciding what to have, go for something which releases energy slowly, such as fruit, porridge or a bagel (or two).