They've done it once, and let's face it, they'll probably do it again. Whether you're just starting out or a seasoned runner, #FF these 20 inspirational women who've taken on the world's greatest race.
Kate Carter, Life & Style and Running Blog Editor at The Guardian
Twitter bio: Life & Style and running blog editor, guardian.co.uk. VLM, Berlin.
Memorable tweet: 'Me to bagel place at marathon expo: "Can I have a toasted bagel?" "We don't have spreads" "Ok just butter" "We don't have butter"'
Amy Lawrenson, Beauty & Fitness Editor at Women's Health
Twitter bio: Beauty & Fitness Editor @UKWomensHealth. Previously @ELLEUK 500 day #runstreak, sub 4-hour marathon. Training to be a PT.
Memorable tweet: 'Emailed myself a reminder and put a kiss on the end. That's nice. But entirely unnecessary.'
Paula Radcliffe, Women's Marathon World Record holder
Twitter bio: Fastest Women's Marathoner in history. Three-time winner of London and New York Marathons
Memorable tweet: 'I run because I am a runner. I am a runner because I run. Good luck to everyone today wherever you are running but especially in LONDON x'
Stacey Duguid, Fashion Director at The Pool
Twitter bio: Freelance writer and fashion consultant and fashion director of www.the-pool.com
Memorable tweet: 'Wine or kale wine or kale wine or kale wine or kale wine or kale wine or kale wine or kale wine or kale wine or kale wine or kale wine or ...'
Rachel Stringer, Presenter BT Sport
Twitter bio: Presenter on BT Sports Panel @BTSP and Reporter on Fletch and Sav @Fletchandsav for BT Sport @BTSport
Memorable tweet: 'Waiting to watch @Pele ...make sandwiches in #Subway'
Melissa Fehr, Blogger
Twitter bio: Expat running, sewing, boat-dwelling lady. I write about running at riverrunner.co.uk and sewing at fehrtrade.com
Memorable tweet: 'The point of cycling is to get chips & a pint in a beer garden somewhere, right?'
Amy Abrahams, Deputy Chief Sub Editor at Glamour
Twitter bio: Deputy Chief Sub Editor at GLAMOUR, theatre lover, fitness writer Marathons: LDN& NY
Memorable tweet: 'I swear there was a time when I only used emojis ironically. Now, I'd consider myself bilingual.'
Susie Chan, Endurance Runner and Blogger
Twitter bio: Endurance Runner; Multistage Ultras, Marathon des Sables, 100 miles. #UKIM2015 Ultimate Direction wearer @UDhydrates
Memorable tweet: 'Bike ride before work = Crunchie at my desk for breakfast. Is it too early to call this a carb load? #eatclean'
Muireann Carey-Campbell, Writer and BOOM Cycle trainer
Twitter bio: Writer. Speaker. Podcaster. Runner. Appreciator of style. Master Trainer at @BOOM_Cycle. Holly Golightly meets Beat Street. Founder of @SpikesandHeels
Memorable tweet: 'Be the bringer of good vibes. Smile at more strangers today. Start a chain reaction of awesome.'
SpeedyBecsRun, Blogger and #ELLEinsider
Twitter bio: Fanatical runner and journo with an adventurous spirit and penchant for fashion and beauty. Also loves a pint of cider or two...
Memorable tweet: 'Doctor: Never seen feet like this before. You did 150 miles in 5 days across the desert? Me: Yup. Doctor: And you would do I again? Me: Yup'
Amy Hughes, Personal Trainer
Twitter bio: Ran 53 #marathons in 53 #UK cities an towns consecutively 2014 raising over £53,000 for Izzys foundation. Brooks ambassador. Cheshire based Personal trainer.
Memorable tweet: 'Run all the way from Oswestry to London for @izzysfoundation and @TheShardLondon wouldn't even let me in for a coffee in gym gear'
Sophie Christabel, Blogger
Twitter bio: I can generally be found running around. I run with @rundemcrew. Marathoner and triathlete! I write a little fitness blog - please pop on over!
Memorable tweet: 'Home workout because my feet are so sore I can't get shoes on. TMI?'
Lisa Jackson, Author
Twitter bio: The best-selling author of Running Made Easy and Adore Yourself Slim, Lisa is a hypnotherapist specialising in weight loss, and an evangelical marathon runner.
Memorable tweet: 'Got the rosebud headband and the red T-shirt I'll be wearing for the 261 Women's Marathon in Majorca @261wm! Now all I have to do is train...'
Fred Butler, Designer
Twitter bio: Living Life In Colour Rainbow haired @fudgehair , Nike familia @Nikelab @rundemcrew , Running LDN Marathon for @themusic_circle @oxfamgb East DRC projects
Memorable tweet: 'Still at my desk. Step away. Tools down. #vlm2015 tomorrow yo! Fresh legs needed for @OxfamRunning @themusic_circle @rundemcrew #yikes'
Christy Turlington, Model and Activist
Twitter bio: Mom, Wife, Daughter, Yogi, Marathoner, Founder @everymomcounts, Author, Living Yoga: Creating A Life Practice, Model. I tweet about Global Maternal Health
Memorable tweet: 'What's status of maternal health in UK? Running #LondonMarathon 2 highlight challenges & solutions @everymomcounts'
Julie Creffield, Blogger and Campaigner
Twitter bio: Think you are #TooFatToRun? RUBBISH!! Let's get 1 million overweight women in the UK running. Download 5weeksto5k & get involved in @OneBigFatRun
Memorable tweet: 'Could have slept for a week last night but no rest for the wicked I have a nation to get moving #RunForYourLife #5weeksto5k #toofattorun'
Liz Yelling, Olympian and Author,
Twitter bio: Two time Olympic marathon runner, Commonwealth medalist, coach, mentor, wife and mum to a beautiful girl and twin boys.
Memorable tweet: 'When it gets tough in a marathon just keep moving forwards!'
Charlie Watson, Blogger
Twitter bio: Marathon Runner. Gin drinker. Fitness blogger. Wannabe cyclist. Pacing the way to healthy without missing out on any of the fun! #Wakeupworkout #Fitfluential
Memorable tweet: 'I would sort of love to be proposed to during a race...as long as I wasn't trying to get a PB! #runnersproblems #BostonMarathon'
Alexandra Heminsley, Author
Twitter bio: Runner, Reader, Writer. Aiming to run 1000miles in 2015. Learning to swim in the ocean.
Memorable tweet: 'What sports bra is Jenni Murray wearing that she can put it on with a broken arm?! I need six arms to get mine on.'
Lornah Kiplagat, World Champion
Twitter bio: Founder of the High Altitude Training Centre Iten (HATC), 4 times World Champion, Founder Lornahsports
Memorable tweet: 'Running at a simulated altitude of 2700 m above sealevel @UKTomTom. Piece of Cake #LondonMarathon'