Marathon course-cutting occurs when runners complete less than an entire course of a marathon before going over the finish line. The standard length of a marathon course is 42.195 kilometers, about 26.2 miles. Course-cutting may be intentional or unintentional and can be achieved by various means.[not verified in body] When done intentionally, course-cutting constitutes cheating.
In October 1979, Rosie Ruiz rode the New York City Subway during the New York City Marathon. In so doing, she qualified for the April 1980 Boston Marathon, and crossed the finish line first in it, but her medal was later revoked because she had taken the Boston subway.
In 2007 Roberto Madrazo, a Mexican presidential candidate in 2006, had his results invalidated in the Berlin Marathon. According to his timing chip, Madrazo skipped two checkpoints on the course and covered one nine-mile segment in 21 minutes (faster than world-record speed for such a distance).
In 2014, Tabatha Hamilton appeared to win the women's category of the Chickamauga Battlefield Marathon with a time of 2:54:21 (2:55:39 gun time). However, officials at the Chattanooga Track Club, which operates the race, grew suspicious upon examining her splits. While Hamilton's timing chip showed she ran the first half in 2:06:31, she appeared to run the second half in 47:30, which would have far exceeded the then-world record for a man in a half-marathon. Additionally, her past race times were not consistent with her supposed performance in Chickamauga. Race officials ultimately concluded Hamilton's timing data showed she could not have possibly run the entire race, and disqualified her.
In 2016, Julie Miller seemingly won the women's 40-44 category in Ironman Canada 2015. However, neither the second-, third- or fourth-place finishers could recall seeing her, with the runner-up even going as far as to publicly confront Miller and ask when she passed her. The other athletes conducted their own investigation after race officials rebuffed them, and compiled evidence that indicated Miller could not possibly have reached specific points at the times she claimed during the marathon segment of the competition. Confronted with this evidence, World Triathlon Corporation disqualified Miller from the 2015 race, as well as Ironman Canada 2013 and the 2014 Vancouver Triathlon. It also took the unprecedented step of banning her from all Ironman events indefinitely.
In 2006, the Washington Post reported that the seventh- and eighth-place women’s finishers of the 2006 Marine Corps Marathon were disqualified. Rick Nealis, the race director, disqualified 350 runners in the 2005 race.
In 2009, the New York Times ran an article on course-cutting, including a map of where about 46 runners in the 2008 New York City Marathon left and reentered the course. “An untold number of [course-cutting] runners escape detection, marathon officials said.” 
- Sarah Lyall (April 10, 2018). "Swim. Bike. Cheat?". The New York Times.
- "1904 Olympics: US Dominance". Young Journalist Academy. 16 January 2015. Retrieved 29 April 2016.
- Jay Maeder (28 October 2003). "Every Unknown Runner Rosie Ruiz, 1980 Chapter 169". New York Daily News. Retrieved 29 April 2016.
- Jennifer Latson (21 April 2015). "How One Woman Won a Marathon and Barely Broke a Sweat". Time. Retrieved 29 April 2016.
- "Electronic Chip Finds Mexican Politician Cheated in Marathon". Associated Press. 9 October 2007. Retrieved 1 November 2010.
- James C. McKinley Jr. (10 October 2007). "For Mexicans, Little Surprise Over Madrazo's Shortcut". New York Times. Retrieved 1 November 2010.
- Alison Wade (November 11, 2014). "Chickamauga Marathon Winner Disqualified for Impossible Splits". Runner's World.
- "Two Runners Caught Cheating At Marine Corps Marathon". Washington Post. November 2, 2006. Retrieved June 3, 2015.
- "In a 26-Mile Slog, a Shortcut Can Be Tempting". The New York Times. October 31, 2009. Retrieved June 3, 2015.
- "Chicago Marathon cheaters: why do they do it?". Chicago Tribune. October 8, 2010. Retrieved June 3, 2015.
- "Running a scam". New York Post. October 31, 2012. Retrieved June 3, 2015.
- 'Deeply shameful': 258 runners caught cheating in Shenzhen's half marathon - The Guardian, 30 November 2018