The London Marathon is one of the biggest community sporting events in the UK, with thousands set to join in and run for a good cause on Sunday April 24.
This year, a whopping 37,000 runners are expected to take part in the 26.2-mile run.
And many of these runners - including our very own What's On writer Emily Chudy - will be running the race for the first time, meaning there are many epic fails that could get you very tired and VERY injured.
Here are 12 of the biggest fails runners should avoid on race day... Make sure you don't commit these marathon sins!
1) Setting off too fast. Just don't. You're not Mo Farah and you never will be.
2) Ambitiously putting yourself in the front pack so you don't get 'held back', and then watching as thousands of runners stream past you.
3) Dodging past people at the start and tiring yourself out.
4) Barging someone out of the way to high five the celebrity you spot running the race.
There are loads of celebs running this year's Marathon , including Dame Kelly Holmes MBE, YouTuber Jim Chapman, and former Made in Chelsea cast member Ashley James... But don't ignore race etiquette to say hi.
5) Convincing yourself that organisers have forgotten to put a mile marker out and you must have done two miles. Then see it and audibly groan.
6) Spending half the race putting your earphones back on your ears... This is the London Marathon, soak up the atmosphere!
7) Taking a gulp of water - then nearly take someone out trying to throw the bottle in the bin.
8) Needing a wee after two miles. Rookie error.
9) Guzzling all your energy gels straight away and slumping after five miles.
10) Spending weeks analysing your performance in training with your fancy watch... Then see it fail to get a GPS signal at the start line.
11) Trying to catch up with the guy in the Spongebob Squarepants suit... And end up eating his dust.
12) Getting to the Houses of Parliament right near the end and thinking you're done, only to realise you still have a whole mile left...
But if you avoid all these pitfalls you'll have the time of your life. And even if you do fall foul you'll still have a great day, and you'll have that shiny medal to treasure at the end...
EVERYTHING YOU NEED TO KNOW ABOUT THE LONDON MARATHON
Have a look at our great photos of last year's London Marathon and the people who took part!
