"Never trust a fart after mile 10"

“Never trust a fart after 3 miles”—and other mile variations of this saying about running—has been printed on many images. The fart could be a signal of poop.

“NEVER TRUST A FART AFTER MILE 20” (shown on a sign, although the post says “Never trust a fart after 20 miles”) was posted on Facebook by Portsmouth Running Group - Catherine Greenway on April 26, 2015. “Distance running teaches many important life lessons. Like never trust a fart after 3 miles” was posted on .X/Twitter by @Mat_Flat on June 16, 2015. “never trust a fart after mile 10” was posted on X/Twitter by Craig Wright on October 3, 2015. “Never trust a fart after 10 miles” was posted on X/Twitter by Luke on October 5, 2015. “Never trust a fart after mile 3” was posted on Facebook by Linden Imhoff Bosarge on April 4, 2026.

Facebook
Portsmouth Running Group ·
Catherine Greenway ·
April 26, 2015 at 9:34 AM ·
Sign seen at the 20 mile mark - ‘Never trust a fart after 20 miles’
(The sign reads, “NEVER TRUST A FART AFTER MILE 20.”—ed.)

X/Twitter
JAGO DIBUJA
@Real_jagoDibuja
Foto: funny-pictures-uk: ‘Never trust a fart after 20 miles’ Sound advice from the crowd watching the… http://tmblr.co/Z8a4vx1jOIeVA
2:37 PM · Apr 26, 2015

X/Twitter
MAC
@SeaOfmanny
Never trust a fart after mile 20. #wisewords
(This is also shown on a sign.—ed.)
9:52 AM · May 3, 2015

X/Twitter
Robbie DeFranco
@robbdef
When running a marathon never trust a fart after mile 20
9:47 PM · May 12, 2015

.X/Twitter
.
@Mat_Flat
“Distance running teaches many important life lessons. Like never trust a fart after 3 miles”
3:31 PM · Jun 16, 2015

X/Twitter
Taco
@borr1920
@mitchell_gauger never trust a fart after mile 3
8:04 PM · Sep 10, 2015

X/Twitter
Craig Wright
@CraigWright1982
@ASICSamerica @BurnTechTV “never trust a fart after mile 10”
9:35 AM · Oct 3, 2015

X/Twitter
Luke
@RunDadSTL
“Never trust a fart after 10 miles”
1:49 PM · Oct 5, 2015

X/Twitter
Bath Runner
@BathRunner
@LetsgorunUk @B_BMarathon @UKRunChat saw a good one on Twitter ‘never trust a fart after 20 miles’ made me giggle lots!
8:53 AM · Oct 22, 2015

X/Twitter
Alison Black
@seacoastrunner
2 of my favorite signs seen at marathons: Run Now. Poop Later. And the other 1: Never Trust a Fart After Mile 20
3:02 PM · May 19, 2016

X/Twitter
Rex Moore
@orangeblood
Best signs I saw at Sunday’s @Marine_Marathon: “Don’t be a Seahawk—Run it in!” And… “Never trust a fart after mile 10.”
10:08 AM · Oct 25, 2017

X/Twitter
Jimmy v
@jamesvdb
Signed up to 1st half marathon. After seeing this advice ‘Never trust a fart after mile twenty’ what other practical advice do you runners out there have?
6:39 AM · Feb 8, 2018

X/Twitter
James Adams
@jamesradams
The old saying in running. “Never trust a fart after 20 miles. Or a kit reviewer who’s been given free shoes”.
3:23 PM · Mar 26, 2018

X/Twitter
Andy O
@AndyO1976
One of the best signs I’ve seen during a race “Never trust a fart after mile 10” 🤣😂
5:42 AM · Feb 20, 2019 from Manchester, England

Facebook
We Know Jack
October 16, 2019 at 3:35 PM ·
True story.
(“NEVER TRUST A FART AFTER 20 MILES #marathon” is shown on a T-shirt.—ed.)

X/Twitter
Daniel 경민 Isaac
@DanielKIsaac
THANK YOU to everyone who encouraged me during training, offered advice and recommendations (NipGuards!), then showed up yesterday with signs (“You’re running better than the government!”, “Never trust a fart after 20 miles!”) and cheers (“Let’s go pink shorts!”) along the way.
1:45 PM · Nov 11, 2021 from Manhattan, NY\

Facebook
David Norton
January 8, 2022 at 6:53 PM ·
“Never trust a fart after mile 7”.
Best marathon running advice ever. Really, really solid advice (potentially).

Bluesky
Peter Heckel
@peter-heckel.bsky.social
Never trust a fart after 30 miles
1:31 AM · Dec 25, 2024

Bluesky
Peter Heckel
@peter-heckel.bsky.social
Never trust a fart after mile 20
12:19 PM · Aug 20, 2025

Bluesky
Linuxrebel
@linuxrebel.org
My Fav Sign from the NYC marathon.
[NYC Marathon sign that says. Never trust a fart after mile 10
ALT]
7:22 PM · Nov 4, 2025

X/Twitter
Greg
@gbm4byu
There is a saying in distance running. “Never trust a fart after mile 20.” I can testify that nothing truer has ever been said.
4:41 PM · Mar 8, 2026

X/Twitter
Production Function
@Piper561
@adamtaggart great running advice is never trust a fart after 10 miles. David explains why.
3:27 PM · Mar 9, 2026

Facebook
Linden Imhoff Bosarge
April 4, 2026 at 9:24 AM ·
“Never trust a fart after mile 3” 🤣 #crescentcityclassic

Bluesky
hollycrow.bsky.social
@hollycrow.bsky.social
[Boston marathon sign never trust a fart after mile 9
ALT]
11:36 AM · Apr 20, 2026