[[quoteright:304:https://static.tvtropes.org/pmwiki/pub/images/run-fat-boy-run01_1797.jpg]]

-> ''"I'm not fat! I'm just... unfit..."''

Dennis Doyle (Creator/SimonPegg) is a clueless, chronically indecisive and slightly overweight ManChild who left his pregnant fiancée Libby (Creator/ThandiweNewton) at the altar five years earlier. He constantly tries to persuade the woman he loves to accept him back into her life, but when he discovers that Libby has found a new partner in the form of American Whit (Creator/HankAzaria), frustration grows, and Dennis vows that for once in his life, he will finish something. This something ends up being the Nike River Run in London. With his friend Gordon ([[Series/BlackBooks Dylan Moran]]) and landlord Mr. Goshdashtidar by his side, Dennis begins training for the marathon he must finish to win the respect of both Libby, and himself.
----
!!This film provides examples of:

* TheAce: Whit; "[[WesternAnimation/WackyRaces Peter Perfect]]" as Dennis calls him.
* AddedAlliterativeAppeal: "[[AlliterativeName Dennis Doyle]] from downstairs".
* AlliterativeName: Dennis Doyle.
* AlwaysSomeoneBetter: Dennis feels this way about Whit for much of the film.
* AmusingInjuries: Gordon stabbing Dennis in the foot with a nail to try and pop a blister, Dennis falling down a staircase into a woman on an exercise ball, and any time Dennis gets hit with a spatula. Averted when Whit breaks Dennis's ankle.
* ArmorPiercingQuestion: [[spoiler:Dennis tells Jake after Jake runs away that he can’t run away from his problems because it doesn’t solve anything and you have to stick at them. Jake asks him, “Is that what you do, Dad?” Dennis has no response, because he himself has made that mistake.]]
* ArtisticLicenseSports: In large televised marathons amateur and professional runners start from different points and the elite runners who are likely to be in with a chance to win start from their own area so Dennis and Whit wouldn't have been on camera to steal the thunder from the elite athletes with their sprinting away from the start and jockeying for position.
* AskAStupidQuestion: [[spoiler: After explicitly pointing out that Dennis is running on a broken ankle, the reporter then asks:]]
--> '''Reporter''': Sir! Sir! How do you feel?\\
'''Dennis''': (in ''tears'', barely cognizant) '''How the [[PrecisionFStrike fuck]] do you think I feel?!'''
* {{Blackmail}}: When Dennis refuses Maya's ultimatum to kick him out if he quits the race and pay his back rent if he doesn't, she whips away his ModestyTowel and takes a polaroid of his naked body. "Deal?" "...Deal."
* CameraAbuse: Dennis "hits the wall" and bounces off the camera.
* CreatorCameo: Director Creator/DavidSchwimmer can be seen giving a glass of beer to Dennis during the race.
* CrankyLandlord: Played with; Mr. G is a cheerful, forgiving type, but [[UglyGuysHotDaughter his daughter]] Maya takes it upon herself to chase Dennis up for the rent.
* ChampionsOnTheInside: [[spoiler: Dennis comes in absolute dead last in the marathon, finishing HOURS after everyone else. But he did it on a broken ankle, he did it to prove he could FINISH something, and he did it despite [[BeyondTheImpossible not physically being able to do it.]] And he still beat Whit, who didn't finish at all.]]
* CheatersNeverProsper: [[spoiler:Whit trips Dennis up, only to be sent to hospital himself while Dennis limps on, and later to get caught out by an action replay.]]
* ConsequenceCombo: There are a lot of carrots and sticks in play, but the clearest example of the trope is Maya's ultimatum - if Dennis finishes the race, she'll call off his back rent. If he doesn't, she'll kick him out.
* {{Crossdresser}}: Who enjoys terrorizing Dennis the security guard, and is later shown [[ChekhovsSkill running the marathon.]]
* DerailingLoveInterests: Whit, who starts off TheAce and gets gradually more {{Control Freak}}y and competitive in direct contrast to Dennis getting more responsible and mature.
* TheDitherer: Dennis's central character flaw is his indecisiveness, which causes him to fail to truly commit to anything he tries and constantly try to find a way out of it. Completing the marathon is essentially his way of overcoming this flaw.
* DownToTheLastPlay: Hugely averted. [[spoiler:Whit is taken out of the race very early, and Dennis severely injured, and the rest of the marathon is spent limping in last place, [[ImplacableMan determined to finish]].]] All of which makes Jake's "Dad, you won!" utterly heartwarming.
* EvilBrit: Whit inverts the trope, as he is an evil American in a British setting as opposed to vice versa.
* TheExsNewJerkass: Libby's new fiancée Whit is [[TheAce everything]] Dennis Doyle is not, from a better runner to having more control over his life to [[BiggerIsBetterInBed having bigger genitalia]] (a thing Dennis discovered with [[NakedPeopleAreFunny much embarrassment]]). Unfortunately for Whit, he destroys his opportunity to marry Libby when he reveals himself to be a big ControlFreak, culminating with him yelling at Libby's son and calling him a "little shit" when he annoys him in the film's final act. [[MamaBear Libby is visibly perturbed by this, and subsequently ditches Whit when it's ultimately revealed he ''deliberately'' tripped Dennis during the marathon, breaking his ankle.]]
* FailedAttemptAtDrama: At the end, after watching Dennis's big moment of triumph, [[spoiler: Whit]] is driven to such a rage that he tries to yank the television away to smash it to pieces. Unfortunately for him, it's screwed on pretty tightly to the wall, meaning that after a few moments of pathetic struggling and fuming he's reduced to just simply switching it off with the button.
* TheFamilyForTheWholeFamily: A low-rent LondonGangster who appears to run a betting syndicate and fence stolen goods, who ''nearly'' breaks Gordon's hand in a piano lid, and who when his bet is threatened hijacks a taxi, drives to the race and... runs alongside Dennis taunting him and ineffectually trying to trip him up. Lampshaded after Mr. G rescues Gordon from the piano incident;
-->'''Mr. G.:''' Your friend is man of honour. He promised to beat shit out of you ''later''!
* FirstFatherWins
* FlatWhat: Libby after Dennis tells her in the bakery he will do the marathon.
* FreezeFrameBonus: At various points in the film, you can see graffiti depicting Dennis's state at that moment. One is of a man clenching his fists and striking a pose on a wall, seen behind Dennis during the TrainingMontage as he runs in and out of bollards. Another obvious one is after [[spoiler:Dennis and Gordon fight]]. Dennis runs around the corner and clearly visible on the wall behind him is of a man hanging from a tree, because at that point, he's at his lowest ebb in the film.
* FromTheMouthsOfBabes: [[spoiler:When Libby leaves Whit for good]], Jake calls Whit a shithead.
* GracefulLoser: Even the NeighbourhoodFriendlyGangsters who bet against Dennis are cheering him on when he crosses the finish line.
* GroinAttack: Several during [[spoiler:the fight between Dennis and Gordon]].
* GuessWhoImMarrying:
* HeartIsWhereTheHomeIs: Both the underdog and the girl he loves are British while the opponent is a jerky American. The movie was going to be set in Chicago so presumably it would have had this plot follow the more American underdog mold, but then Creator/SimonPegg bought the script.
* HeroicBSOD: Dennis has one after [[spoiler:Libby agrees to marry Whit.]] He's so depressed he drops out of the race, has a WimpFight with Gordon and it takes a TheReasonYouSuckSpeech from Mr. G. and [[spoiler:Jake running away]] to get him to pull himself out of it.
* IGaveMyWord: Somewhat justified despite the HonorBeforeReason, since his ability to keep a promise is what Dennis is ''really' trying to prove.
* ImplacableMan[=/=]TheDeterminator: Dennis, [[strike:running]] limping the best part of a ''marathon'' on a sprained, implied to be ''broken'' ankle because [[IGaveMyWord he promised he would, dammit!]]
* InconvenientItch: When he first starts working out, Dennis gets a nasty, itchy rash on his crotch that he absolutely has to scratch... as he is at work as a security guard in a lingerie shop. One can guess what this [[AccidentalPervert looks like]].
* IResembleThatRemark: In Libby's bakery;
-->'''Libby:''' You can't even finish your sentence! \\
'''Dennis:''' Oh... don't... don't... don't be... what's the word?
* IronicEcho: "No, but you can watch me do it."
* JerkJock: Whit.
* JerkWithAHeartOfGold: Gordon. He steals from people and bets everything on Dennis. However, he cares about him, Libby and Jake. Just look at the scene where [[spoiler: Jake has run away and Dennis tells Gordon about this.]]
* KentBrockmanNews: The overexcitable reporter. "He ''deliberately'' tripped him! ''Bastard!'' Sorry, got carried away again..."
** "And, what's that? ''[overjoyed]'' He's got a ''son!'' I didn't know he had a son! Did you know he had a son!?"
** "Yes! ''Yes''! ''Keep going you beautiful man''!"
* KickTheDog: When Jake won't stop messing around with Whit's hospital bed, Whit loses it and shouts at him, "Goddamn it! Will you stop messing around with the bed, you little shit?!" He does this in front of Libby, and she's ''not'' happy about it.
* LawyerFriendlyCameo: Dennis and Whit are running in an annual marathon in London on a Sunday, with space for a number of charity runners to enter after the general closing date, that is most definitely ''not'' the London Marathon.
* ManChild: Dennis's whole problem.
* ModestyTowel: Played with twice. Whit drops his in the changing room, giving Dennis an eyeful, and Maya whips Dennis' away after he gets out of the shower in order to take a blackmail photo.
* NeverMyFault: Dennis blames his problems that he caused on other people.
* NewscasterCameo: BBC Breakfast presenter Chris Hollins AsHimself, commentating on the race with Denise Lewis.
* NoodleIncident: Gordon's one serious relationship somehow ended with "a broken collarbone and a dead meerkat." There's also the question of what exactly was the ''most'' disgusting fluid he's ever had in his eye, and the circumstances in which it came to be there.
* OnlyOneName: Subverted with Whit. The doctor in the hospital who treats his leg reveals Whit's surname is Bloom.
* OverlyNarrowSuperlative: "That's the second most disgusting fluid I've ever had in my eye!"
* PantsFree: When Gordon invites Dennis into his apartment, he's leaning over the balcony. At the end of the conversation we see him shot from behind, revealing that he's naked from the waist down. At the end of the movie, he invites two beautiful girls onto his boat... again, no pants.
* ParentWithNewParamour: Averted at first, Jake is pretty impressed with Whit, which to Dennis just makes him even more [[AlwaysSomeoneBetter depressingly superior]]. However, they're never as close as he is with his dad, and when Jake really starts going off Whit you know the guy's doomed...
* PrecisionFStrike: Jake on Whit: "What a shithead..."
** A hilarious one the second time Dennis realises he's locked himself out of his flat: "FUCK!"
* ProductPlacement: For Nike, shamelessly. The "Nike River Run" is sponsored by Nike, there are Nike banners every 20 feet of the race, and the commentators and journalists keep saying "Nike." [[SelfDemonstratingArticle Nike.]]
* PleasePutSomeClothesOn: The locker room scene. See EnforcedMethodActing.
* RawEggsMakeYouStronger: As part of his TrainingMontage, Dennis attempts to drink about six raw eggs at once, but immediately spits them back up.
* ReactiveContinuousScream: Dennis and Gordon, when Dennis wakes up with an hour to get to the starting line.
* TheReasonYouSuckSpeech: Whit takes that relationship-as-marathon metaphor and drags it right out of the subtext to slap it in Dennis' stunned face.
** The always cheerful and kind Mr. G is devastated when Dennis drops out of the race, and delivers a seriously good one - basically ''in tears'' - to get Dennis to pull himself together.
* TheRunaway: [[spoiler:Dennis is snapped out of his HeroicBSOD when a panicking Libby tells him Jake has run away. When Dennis finds him, Jake tells him he did it because he was upset that the girl he liked likes another boy more because he has a ponytail.]]
* RunawayBride: Dennis is a runaway groom.
* ShoutOut:
** Dennis refers to Whit as "[[WesternAnimation/WackyRaces Peter Perfect]]".
** The reporter refers to ''The Loneliness Of The Long-Distance Runner'', a short story by Alan Sillitoe.
** Dennis attempting to drink raw eggs during the TrainingMontage, as well as the camera angle during that scene, is a reference to ''Film/{{Rocky}}''.
* TheyWastedAPerfectlyGoodSandwich: The spaghetti bolognese, becomes a plot point later on.
* TitleDrop: By the crossdresser, and later by Whit as he pulls away in the race.
* TrainingMontage: Parodied and played straight side-by-side.
* TurnedOffByTheJerkass: Dennis' ex-girlfriend is quite okay with her new boyfriend Wint, who is TheAce (at least comparatively to Dennis) and Dennis can see that he is a jerk but cannot convince her of it, but she ditches him the very second he is irritated about her son changing channels on the TV of the hospital room he is staying at after a minor accident on a marathon and yells at the kid "choose one channel and stick to it, [[PrecisionFStrike you little shit]]!"
* UglyGuysHotDaughter: Maya.
* UglyGuyHotWife: Libby is ''way'' out of Dennis' league, HollywoodPudgy or not.
* TheUnpronounceable: Mr Gostust... Goshdash... Mr G. [[AllThereInTheScript For the record: Goshdashtidar.]]
* VillainsOutShopping: At one point while Dennis is training for the marathon, he sees Whit doing the same, and jumps into a bush so Whit doesn't see him.
* VisualPun: Whit and Dennis edge their way past a pair of runners dressed as a tortoise and a hare.
* WimpFight: [[https://www.youtube.com/watch?v=nUJS7OyOK2U A stellar example]].
* YaoiFangirl: The guys are in the middle of a NotWhatItLooksLike moment in a taxi when it stops in front of an attractive woman, who seems to like what she sees.
* YouAreFat: The TitleDrop, courtesy of the transsexual kleptomaniac. Dennis is really a [[HollywoodPudgy fairly scrawny guy with a beer gut]], but that doesn't stop him being self-conscious about it.
----